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Dr. Laurie Starkey

Dr. Laurie Starkey

Carboxylic Acids

Slide Duration:

Table of Contents

I. Introduction to Organic Molecules
Introduction and Drawing Structures

49m 51s

Intro
0:00
Organic Chemistry
0:07
Organic
0:08
Inorganic
0:26
Examples of Organic Compounds
1:16
Review Some Chemistry Basics
5:23
Electrons
5:42
Orbitals (s,p,d,f)
6:12
Review Some Chemistry Basics
7:35
Elements & Noble Gases
7:36
Atom & Valance Shell
8:47
Review Some Chemistry Basics
11:33
Electronegative Elements
11:34
Which Is More Electronegative, C or N?
13:45
Ionic & Covalent Bonds
14:07
Ionic Bonds
14:08
Covalent Bonds
16:17
Polar Covalent Bonds
19:35
Polar Covalent Bonds & Electronegativities
19:37
Polarity of Molecules
22:56
Linear molecule
23:07
Bent Molecule
23:53
No Polar Bonds
24:21
Ionic
24:52
Line Drawings
26:36
Line Drawing Overview
26:37
Line Drawing: Example 1
27:12
Line Drawing: Example 2
29:14
Line Drawing: Example 3
29:51
Line Drawing: Example 4
30:34
Line Drawing: Example 5
31:21
Line Drawing: Example 6
32:41
Diversity of Organic Compounds
33:57
Diversity of Organic Compounds
33:58
Diversity of Organic Compounds, cont.
39:16
Diversity of Organic Compounds, cont.
39:17
Examples of Polymers
45:26
Examples of Polymers
45:27
Lewis Structures & Resonance

44m 25s

Intro
0:00
Lewis Structures
0:08
How to Draw a Lewis Structure
0:09
Examples
2:20
Lewis Structures
6:25
Examples: Lewis Structure
6:27
Determining Formal Charges
8:48
Example: Determining Formal Charges for Carbon
10:11
Example: Determining Formal Charges for Oxygen
11:02
Lewis Structures
12:08
Typical, Stable Bonding Patterns: Hydrogen
12:11
Typical, Stable Bonding Patterns: Carbon
12:58
Typical, Stable Bonding Patterns: Nitrogen
13:25
Typical, Stable Bonding Patterns: Oxygen
13:54
Typical, Stable Bonding Patterns: Halogen
14:16
Lewis Structure Example
15:17
Drawing a Lewis Structure for Nitric Acid
15:18
Resonance
21:58
Definition of Resonance
22:00
Delocalization
22:07
Hybrid Structure
22:38
Rules for Estimating Stability of Resonance Structures
26:04
Rule Number 1: Complete Octets
26:10
Rule Number 2: Separation of Charge
28:13
Rule Number 3: Negative and Positive Charges
30:02
Rule Number 4: Equivalent
31:06
Looking for Resonance
32:09
Lone Pair Next to a p Bond
32:10
Vacancy Next to a p Bond
33:53
p Bond Between Two Different Elements
35:00
Other Type of Resonance: Benzene
36:06
Resonance Example
37:29
Draw and Rank Resonance Forms
37:30
Acid-Base Reactions

1h 7m 46s

Intro
0:00
Acid-Base Reactions
0:07
Overview
0:08
Lewis Acid and Lewis Base
0:30
Example 1: Lewis Acid and Lewis Base
1:53
Example 2: Lewis Acid and Lewis Base
3:04
Acid-base Reactions
4:54
Bonsted-Lowry Acid and Bonsted-Lowry Base
4:56
Proton Transfer Reaction
5:36
Acid-Base Equilibrium
8:14
Two Acids in Competition = Equilibrium
8:15
Example: Which is the Stronger Acid?
8:40
Periodic Trends for Acidity
12:40
Across Row
12:41
Periodic Trends for Acidity
19:48
Energy Diagram
19:50
Periodic Trends for Acidity
21:28
Down a Family
21:29
Inductive Effects on Acidity
25:52
Example: Which is the Stronger Acid?
25:54
Other Electron-Withdrawing Group (EWG)
30:37
Inductive Effects on Acidity
32:55
Inductive Effects Decrease with Distance
32:56
Resonance Effects on Acidity
36:35
Examples of Resonance Effects on Acidity
36:36
Resonance Effects on Acidity
41:15
Small and Large Amount of Resonance
41:17
Acid-Base Example
43:10
Which is Most Acidic? Which is the Least Acidic?
43:12
Acid-Base Example
49:26
Which is the Stronger Base?
49:27
Acid-Base Example
53:58
Which is the Strongest Base?
53:59
Common Acids/Bases
00:45
Common Acids/Bases
00:46
Example: Determine the Direction of Equilibrium
04:51
Structures and Properties of Organic Molecules

1h 23m 35s

Intro
0:00
Orbitals and Bonding
0:20
Atomic Orbitals (AO)
0:21
Molecular Orbitals (MO)
1:46
Definition of Molecular Orbitals
1:47
Example 1: Formation of Sigma Bond and Molecular Orbitals
2:20
Molecular Orbitals (MO)
5:25
Example 2: Formation of Pi Bond
5:26
Overlapping E Levels of MO's
7:28
Energy Diagram
7:29
Electronic Transitions
9:18
Electronic Transitions
9:23
Hybrid Orbitals
12:04
Carbon AO
12:06
Hybridization
13:51
Hybrid Orbitals
15:02
Examples of Hybrid Orbitals
15:05
Example: Assign Hybridization
20:31
3-D Sketches
24:05
sp3
24:24
sp2
25:28
sp
27:41
3-D Sketches of Molecules
29:07
3-D Sketches of Molecules 1
29:08
3-D Sketches of Molecules 2
32:29
3-D Sketches of Molecules 3
35:36
3D Sketch
37:20
How to Draw 3D Sketch
37:22
Example 1: Drawing 3D Sketch
37:50
Example 2: Drawing 3D Sketch
43:04
Hybridization and Resonance
46:06
Example: Hybridization and Resonance
46:08
Physical Properties
49:55
Water Solubility, Boiling Points, and Intermolecular Forces
49:56
Types of 'Nonbonding' Interactions
51:47
Dipole-Dipole
52:37
Definition of Dipole-Dipole
52:39
Example: Dipole-Dipole Bonding
53:27
Hydrogen Bonding
57:14
Definition of Hydrogen Bonding
57:15
Example: Hydrogen Bonding
58:05
Van Der Waals/ London Forces
03:11
Van Der Waals/ London Forces
03:12
Example: Van Der Waals/ London Forces
04:59
Water Solubility
08:32
Water Solubility
08:34
Example: Water Solubility
09:05
Example: Acetone
11:29
Isomerism
13:51
Definition of Isomers
13:53
Constitutional Isomers and Example
14:17
Stereoisomers and Example
15:34
Introduction to Functional Groups
17:06
Functional Groups: Example, Abbreviation, and Name
17:07
Introduction to Functional Groups
20:48
Functional Groups: Example, Abbreviation, and Name
20:49
Alkane Structures

1h 13m 38s

Intro
0:00
Nomenclature of Alkanes
0:12
Nomenclature of Alkanes and IUPAC Rules
0:13
Examples: Nomenclature of Alkanes
4:38
Molecular Formula and Degrees of Unsaturation (DU)
17:24
Alkane Formula
17:25
Example: Heptane
17:58
Why '2n+2' Hydrogens?
18:35
Adding a Ring
19:20
Adding a p Bond
19:42
Example 1: Determine Degrees of Unsaturation (DU)
20:17
Example 2: Determine Degrees of Unsaturation (DU)
21:35
Example 3: Determine DU of Benzene
23:30
Molecular Formula and Degrees of Unsaturation (DU)
24:41
Example 4: Draw Isomers
24:42
Physical properties of Alkanes
29:17
Physical properties of Alkanes
29:18
Conformations of Alkanes
33:40
Conformational Isomers
33:42
Conformations of Ethane: Eclipsed and Staggered
34:40
Newman Projection of Ethane
36:15
Conformations of Ethane
40:38
Energy and Degrees Rotated Diagram
40:41
Conformations of Butane
42:28
Butane
42:29
Newman Projection of Butane
43:35
Conformations of Butane
44:25
Energy and Degrees Rotated Diagram
44:30
Cycloalkanes
51:26
Cyclopropane and Cyclobutane
51:27
Cyclopentane
53:56
Cycloalkanes
54:56
Cyclohexane: Chair, Boat, and Twist Boat Conformations
54:57
Drawing a Cyclohexane Chair
57:58
Drawing a Cyclohexane Chair
57:59
Newman Projection of Cyclohexane
02:14
Cyclohexane Chair Flips
04:06
Axial and Equatorial Groups
04:10
Example: Chair Flip on Methylcyclohexane
06:44
Cyclohexane Conformations Example
09:01
Chair Conformations of cis-1-t-butyl-4-methylcyclohexane
09:02
Stereochemistry

1h 40m 54s

Intro
0:00
Stereochemistry
0:10
Isomers
0:11
Stereoisomer Examples
1:30
Alkenes
1:31
Cycloalkanes
2:35
Stereoisomer Examples
4:00
Tetrahedral Carbon: Superimposable (Identical)
4:01
Tetrahedral Carbon: Non-Superimposable (Stereoisomers)
5:18
Chirality
7:18
Stereoisomers
7:19
Chiral
8:05
Achiral
8:29
Example: Achiral and Chiral
8:45
Chirality
20:11
Superimposable, Non-Superimposable, Chiral, and Achiral
20:12
Nomenclature
23:00
Cahn-Ingold-Prelog Rules
23:01
Nomenclature
29:39
Example 1: Nomenclature
29:40
Example 2: Nomenclature
31:49
Example 3: Nomenclature
33:24
Example 4: Nomenclature
35:39
Drawing Stereoisomers
36:58
Drawing (S)-2-bromopentane
36:59
Drawing the Enantiomer of (S)-2-bromopentane: Method 1
38:47
Drawing the Enantiomer of (S)-2-bromopentane: Method 2
39:35
Fischer Projections
41:47
Definition of Fischer Projections
41:49
Drawing Fischer Projection
43:43
Use of Fisher Projection: Assigning Configuration
49:13
Molecules with Two Chiral Carbons
51:49
Example A
51:42
Drawing Enantiomer of Example A
53:26
Fischer Projection of A
54:25
Drawing Stereoisomers, cont.
59:40
Drawing Stereoisomers Examples
59:41
Diastereomers
01:48
Drawing Stereoisomers
06:37
Draw All Stereoisomers of 2,3-dichlorobutane
06:38
Molecules with Two Chiral Centers
10:22
Draw All Stereoisomers of 2,3-dichlorobutane, cont.
10:23
Optical Activity
14:10
Chiral Molecules
14:11
Angle of Rotation
14:51
Achiral Species
16:46
Physical Properties of Stereoisomers
17:11
Enantiomers
17:12
Diastereomers
18:01
Example
18:26
Physical Properties of Stereoisomers
23:05
When Do Enantiomers Behave Differently?
23:06
Racemic Mixtures
28:18
Racemic Mixtures
28:21
Resolution
29:52
Unequal Mixtures of Enantiomers
32:54
Enantiomeric Excess (ee)
32:55
Unequal Mixture of Enantiomers
34:43
Unequal Mixture of Enantiomers
34:44
Example: Finding ee
36:38
Example: Percent of Composition
39:46
II. Understanding Organic Reactions
Nomenclature

1h 53m 47s

Intro
0:00
Cycloalkane Nomenclature
0:17
Cycloalkane Nomenclature and Examples
0:18
Alkene Nomenclature
6:28
Alkene Nomenclature and Examples
6:29
Alkene Nomenclature: Stereochemistry
15:07
Alkenes With Two Groups: Cis & Trans
15:08
Alkenes With Greater Than Two Groups: E & Z
18:26
Alkyne Nomenclature
24:46
Alkyne Nomenclature and Examples
24:47
Alkane Has a Higher Priority Than Alkyne
28:25
Alcohol Nomenclature
29:24
Alcohol Nomenclature and Examples
29:25
Alcohol FG Has Priority Over Alkene/yne
33:41
Ether Nomenclature
36:32
Ether Nomenclature and Examples
36:33
Amine Nomenclature
42:59
Amine Nomenclature and Examples
43:00
Amine Nomenclature
49:45
Primary, Secondary, Tertiary, Quaternary Salt
49:46
Aldehyde Nomenclature
51:37
Aldehyde Nomenclature and Examples
51:38
Ketone Nomenclature
58:43
Ketone Nomenclature and Examples
58:44
Aromatic Nomenclature
05:02
Aromatic Nomenclature and Examples
05:03
Aromatic Nomenclature, cont.
09:09
Ortho, Meta, and Para
09:10
Aromatic Nomenclature, cont.
13:27
Common Names for Simple Substituted Aromatic Compounds
13:28
Carboxylic Acid Nomenclature
16:35
Carboxylic Acid Nomenclature and Examples
16:36
Carboxylic Acid Derivatives
22:28
Carboxylic Acid Derivatives
22:42
General Structure
23:10
Acid Halide Nomenclature
24:48
Acid Halide Nomenclature and Examples
24:49
Anhydride Nomenclature
28:10
Anhydride Nomenclature and Examples
28:11
Ester Nomenclature
32:50
Ester Nomenclature
32:51
Carboxylate Salts
38:51
Amide Nomenclature
40:02
Amide Nomenclature and Examples
40:03
Nitrile Nomenclature
45:22
Nitrile Nomenclature and Examples
45:23
Chemical Reactions

51m 1s

Intro
0:00
Chemical Reactions
0:06
Reactants and Products
0:07
Thermodynamics
0:50
Equilibrium Constant
1:06
Equation
2:35
Organic Reaction
3:05
Energy vs. Progress of Rxn Diagrams
3:48
Exothermic Reaction
4:02
Endothermic Reaction
6:54
Estimating ΔH rxn
9:15
Bond Breaking
10:03
Bond Formation
10:25
Bond Strength
11:35
Homolytic Cleavage
11:59
Bond Dissociation Energy (BDE) Table
12:29
BDE for Multiple Bonds
14:32
Examples
17:35
Kinetics
20:35
Kinetics
20:36
Examples
21:49
Reaction Rate Variables
23:15
Reaction Rate Variables
23:16
Increasing Temperature, Increasing Rate
24:08
Increasing Concentration, Increasing Rate
25:39
Decreasing Energy of Activation, Increasing Rate
27:49
Two-Step Mechanisms
30:06
E vs. POR Diagram (2-step Mechanism)
30:07
Reactive Intermediates
33:03
Reactive Intermediates
33:04
Example: A Carbocation
35:20
Carbocation Stability
37:24
Relative Stability of Carbocation
37:25
Alkyl groups and Hyperconjugation
38:45
Carbocation Stability
41:57
Carbocation Stabilized by Resonance: Allylic
41:58
Carbocation Stabilized by Resonance: Benzylic
42:59
Overall Carbocation Stability
44:05
Free Radicals
45:05
Definition and Examples of Free Radicals
45:06
Radical Mechanisms
49:40
Example: Regular Arrow
49:41
Example: Fish-Hook Arrow
50:17
Free Radical Halogenation

26m 23s

Intro
0:00
Free Radical Halogenation
0:06
Free Radical Halogenation
0:07
Mechanism: Initiation
1:27
Mechanism: Propagation Steps
2:21
Free Radical Halogenation
5:33
Termination Steps
5:36
Example 1: Terminations Steps
6:00
Example 2: Terminations Steps
6:18
Example 3: Terminations Steps
7:43
Example 4: Terminations Steps
8:04
Regiochemistry of Free Radical Halogenation
9:32
Which Site/Region Reacts and Why?
9:34
Bromination and Rate of Reaction
14:03
Regiochemistry of Free Radical Halogenation
14:30
Chlorination
14:31
Why the Difference in Selectivity?
19:58
Allylic Halogenation
20:53
Examples of Allylic Halogenation
20:55
Substitution Reactions

1h 48m 5s

Intro
0:00
Substitution Reactions
0:06
Substitution Reactions Example
0:07
Nucleophile
0:39
Electrophile
1:20
Leaving Group
2:56
General Reaction
4:13
Substitution Reactions
4:43
General Reaction
4:46
Substitution Reaction Mechanisms: Simultaneous
5:08
Substitution Reaction Mechanisms: Stepwise
5:34
SN2 Substitution
6:21
Example of SN2 Mechanism
6:22
SN2 Kinetics
7:58
Rate of SN2
9:10
Sterics Affect Rate of SN2
9:12
Rate of SN2 (By Type of RX)
14:13
SN2: E vs. POR Diagram
17:26
E vs. POR Diagram
17:27
Transition State (TS)
18:24
SN2 Transition State, Kinetics
20:58
SN2 Transition State, Kinetics
20:59
Hybridization of TS Carbon
21:57
Example: Allylic LG
23:34
Stereochemistry of SN2
25:46
Backside Attack and Inversion of Stereochemistry
25:48
SN2 Summary
29:56
Summary of SN2
29:58
Predict Products (SN2)
31:42
Example 1: Predict Products
31:50
Example 2: Predict Products
33:38
Example 3: Predict Products
35:11
Example 4: Predict Products
36:11
Example 5: Predict Products
37:32
SN1 Substitution Mechanism
41:52
Is This Substitution? Could This Be an SN2 Mechanism?
41:54
SN1 Mechanism
43:50
Two Key Steps: 1. Loss of LG
43:53
Two Key Steps: 2. Addition of nu
45:11
SN1 Kinetics
47:17
Kinetics of SN1
47:18
Rate of SN1 (By RX type)
48:44
SN1 E vs. POR Diagram
49:49
E vs. POR Diagram
49:51
First Transition Stage (TS-1)
51:48
Second Transition Stage (TS-2)
52:56
Stereochemistry of SN1
53:44
Racemization of SN1 and Achiral Carbocation Intermediate
53:46
Example
54:29
SN1 Summary
58:25
Summary of SN1
58:26
SN1 or SN2 Mechanisms?
00:40
Example 1: SN1 or SN2 Mechanisms
00:42
Example 2: SN1 or SN2 Mechanisms
03:00
Example 3: SN1 or SN2 Mechanisms
04:06
Example 4: SN1 or SN2 Mechanisms
06:17
SN1 Mechanism
09:12
Three Steps of SN1 Mechanism
09:13
SN1 Carbocation Rearrangements
14:50
Carbocation Rearrangements Example
14:51
SN1 Carbocation Rearrangements
20:46
Alkyl Groups Can Also Shift
20:48
Leaving Groups
24:26
Leaving Groups
24:27
Forward or Reverse Reaction Favored?
26:00
Leaving Groups
29:59
Making poor LG Better: Method 1
30:00
Leaving Groups
34:18
Making poor LG Better: Tosylate (Method 2)
34:19
Synthesis Problem
38:15
Example: Provide the Necessary Reagents
38:16
Nucleophilicity
41:10
What Makes a Good Nucleophile?
41:11
Nucleophilicity
44:45
Periodic Trends: Across Row
44:47
Periodic Trends: Down a Family
46:46
Elimination Reactions

1h 11m 43s

Intro
0:00
Elimination Reactions: E2 Mechanism
0:06
E2 Mechanism
0:08
Example of E2 Mechanism
1:01
Stereochemistry of E2
4:48
Anti-Coplanar & Anti-Elimination
4:50
Example 1: Stereochemistry of E2
5:34
Example 2: Stereochemistry of E2
10:39
Regiochemistry of E2
13:04
Refiochemistry of E2 and Zaitsev's Rule
13:05
Alkene Stability
17:39
Alkene Stability
19:20
Alkene Stability Examples
19:22
Example 1: Draw Both E2 Products and Select Major
21:57
Example 2: Draw Both E2 Products and Select Major
25:02
SN2 Vs. E2 Mechanisms
29:06
SN2 Vs. E2 Mechanisms
29:07
When Do They Compete?
30:34
SN2 Vs. E2 Mechanisms
31:23
Compare Rates
31:24
SN2 Vs. E2 Mechanisms
36:34
t-BuBr: What If Vary Base?
36:35
Preference for E2 Over SN2 (By RX Type)
40:42
E1 Elimination Mechanism
41:51
E1 - Elimination Unimolecular
41:52
E1 Mechanism: Step 1
44:14
E1 Mechanism: Step 2
44:48
E1 Kinetics
46:58
Rate = k[RCI]
47:00
E1 Rate (By Type of Carbon Bearing LG)
48:31
E1 Stereochemistry
49:49
Example 1: E1 Stereochemistry
49:51
Example 2: E1 Stereochemistry
52:31
Carbocation Rearrangements
55:57
Carbocation Rearrangements
56:01
Product Mixtures
57:20
Predict the Product: SN2 vs. E2
59:58
Example 1: Predict the Product
00:00
Example 2: Predict the Product
02:10
Example 3: Predict the Product
04:07
Predict the Product: SN2 vs. E2
06:06
Example 4: Predict the Product
06:07
Example 5: Predict the Product
07:29
Example 6: Predict the Product
07:51
Example 7: Predict the Product
09:18
III. Alkanes, Alkenes, & Alkynes
Alkenes

36m 39s

Intro
0:00
Alkenes
0:12
Definition and Structure of Alkenes
0:13
3D Sketch of Alkenes
1:53
Pi Bonds
3:48
Alkene Stability
4:57
Alkyl Groups Attached
4:58
Trans & Cis
6:20
Alkene Stability
8:42
Pi Bonds & Conjugation
8:43
Bridgehead Carbons & Bredt's Rule
10:22
Measuring Stability: Hydrogenation Reaction
11:40
Alkene Synthesis
12:01
Method 1: E2 on Alkyl Halides
12:02
Review: Stereochemistry
16:17
Review: Regiochemistry
16:50
Review: SN2 vs. E2
17:34
Alkene Synthesis
18:57
Method 2: Dehydration of Alcohols
18:58
Mechanism
20:08
Alkene Synthesis
23:26
Alcohol Dehydration
23:27
Example 1: Comparing Strong Acids
26:59
Example 2: Mechanism for Dehydration Reaction
29:00
Example 3: Transform
32:50
Reactions of Alkenes

2h 8m 44s

Intro
0:00
Reactions of Alkenes
0:05
Electrophilic Addition Reaction
0:06
Addition of HX
2:02
Example: Regioselectivity & 2 Steps Mechanism
2:03
Markovnikov Addition
5:30
Markovnikov Addition is Favored
5:31
Graph: E vs. POR
6:33
Example
8:29
Example: Predict and Consider the Stereochemistry
8:30
Hydration of Alkenes
12:31
Acid-catalyzed Addition of Water
12:32
Strong Acid
14:20
Hydration of Alkenes
15:20
Acid-catalyzed Addition of Water: Mechanism
15:21
Hydration vs. Dehydration
19:51
Hydration Mechanism is Exact Reverse of Dehydration
19:52
Example
21:28
Example: Hydration Reaction
21:29
Alternative 'Hydration' Methods
25:26
Oxymercuration-Demercuration
25:27
Oxymercuration Mechanism
28:55
Mechanism of Oxymercuration
28:56
Alternative 'Hydration' Methods
30:51
Hydroboration-Oxidation
30:52
Hydroboration Mechanism
33:22
1-step (concerted)
33:23
Regioselective
34:45
Stereoselective
35:30
Example
35:58
Example: Hydroboration-Oxidation
35:59
Example
40:42
Example: Predict the Major Product
40:43
Synthetic Utility of 'Alternate' Hydration Methods
44:36
Example: Synthetic Utility of 'Alternate' Hydration Methods
44:37
Flashcards
47:28
Tips On Using Flashcards
47:29
Bromination of Alkenes
49:51
Anti-Addition of Br₂
49:52
Bromination Mechanism
53:16
Mechanism of Bromination
53:17
Bromination Mechanism
55:42
Mechanism of Bromination
55:43
Bromination: Halohydrin Formation
58:54
Addition of other Nu: to Bromonium Ion
58:55
Mechanism
00:08
Halohydrin: Regiochemistry
03:55
Halohydrin: Regiochemistry
03:56
Bromonium Ion Intermediate
04:26
Example
09:28
Example: Predict Major Product
09:29
Example Cont.
10:59
Example: Predict Major Product Cont.
11:00
Catalytic Hydrogenation of Alkenes
13:19
Features of Catalytic Hydrogenation
13:20
Catalytic Hydrogenation of Alkenes
14:48
Metal Surface
14:49
Heterogeneous Catalysts
15:29
Homogeneous Catalysts
16:08
Catalytic Hydrogenation of Alkenes
17:44
Hydrogenation & Pi Bond Stability
17:45
Energy Diagram
19:22
Catalytic Hydrogenation of Dienes
20:40
Hydrogenation & Pi Bond Stability
20:41
Energy Diagram
23:31
Example
24:14
Example: Predict Product
24:15
Oxidation of Alkenes
27:21
Redox Review
27:22
Epoxide
30:26
Diol (Glycol)
30:54
Ketone/ Aldehyde
31:13
Epoxidation
32:08
Epoxidation
32:09
General Mechanism
36:32
Alternate Epoxide Synthesis
37:38
Alternate Epoxide Synthesis
37:39
Dihydroxylation
41:10
Dihydroxylation
41:12
General Mechanism (Concerted Via Cycle Intermediate)
42:38
Ozonolysis
44:22
Ozonolysis: Introduction
44:23
Ozonolysis: Is It Good or Bad?
45:05
Ozonolysis Reaction
48:54
Examples
51:10
Example 1: Ozonolysis
51:11
Example
53:25
Radical Addition to Alkenes
55:05
Recall: Free-Radical Halogenation
55:15
Radical Mechanism
55:45
Propagation Steps
58:01
Atom Abstraction
58:30
Addition to Alkene
59:11
Radical Addition to Alkenes
59:54
Markovnivok (Electrophilic Addition) & anti-Mark. (Radical Addition)
59:55
Mechanism
01:03
Alkene Polymerization
05:35
Example: Alkene Polymerization
05:36
Alkynes

1h 13m 19s

Intro
0:00
Structure of Alkynes
0:04
Structure of Alkynes
0:05
3D Sketch
2:30
Internal and Terminal
4:03
Reductions of Alkynes
4:36
Catalytic Hydrogenation
4:37
Lindlar Catalyst
5:25
Reductions of Alkynes
7:24
Dissolving Metal Reduction
7:25
Oxidation of Alkynes
9:24
Ozonolysis
9:25
Reactions of Alkynes
10:56
Addition Reactions: Bromination
10:57
Addition of HX
12:24
Addition of HX
12:25
Addition of HX
13:36
Addition of HX: Mechanism
13:37
Example
17:38
Example: Transform
17:39
Hydration of Alkynes
23:35
Hydration of Alkynes
23:36
Hydration of Alkynes
26:47
Hydration of Alkynes: Mechanism
26:49
'Hydration' via Hydroboration-Oxidation
32:57
'Hydration' via Hydroboration-Oxidation
32:58
Disiamylborane
33:28
Hydroboration-Oxidation Cont.
34:25
Alkyne Synthesis
36:17
Method 1: Alkyne Synthesis By Dehydrohalogenation
36:19
Alkyne Synthesis
39:06
Example: Transform
39:07
Alkyne Synthesis
41:21
Method 2 & Acidity of Alkynes
41:22
Conjugate Bases
43:06
Preparation of Acetylide Anions
49:55
Preparation of Acetylide Anions
49:57
Alkyne Synthesis
53:40
Synthesis Using Acetylide Anions
53:41
Example 1: Transform
57:04
Example 2: Transform
01:07
Example 3: Transform
06:22
IV. Alcohols
Alcohols, Part I

59m 52s

Intro
0:00
Alcohols
0:11
Attributes of Alcohols
0:12
Boiling Points
2:00
Water Solubility
5:00
Water Solubility (Like Dissolves Like)
5:01
Acidity of Alcohols
9:39
Comparison of Alcohols Acidity
9:41
Preparation of Alkoxides
13:03
Using Strong Base Like Sodium Hydride
13:04
Using Redox Reaction
15:36
Preparation of Alkoxides
17:41
Using K°
17:42
Phenols Are More Acidic Than Other Alcohols
19:51
Synthesis of Alcohols, ROH
21:43
Synthesis of Alcohols from Alkyl Halides, RX (SN2 or SN1)
21:44
Synthesis of Alcohols, ROH
25:08
Unlikely on 2° RX (E2 Favored)
25:09
Impossible on 3° RX (E2) and Phenyl/Vinyl RX (N/R)
25:47
Synthesis of Alcohols, ROH
26:26
SN1 with H₂O 'Solvolysis' or 'Hydrolysis'
26:27
Carbocation Can Rearrange
29:00
Synthesis of Alcohols, ROH
30:08
Synthesis of Alcohols From Alkenes: Hydration
30:09
Synthesis of Alcohols From Alkenes: Oxidation/Diol
32:20
Synthesis of Alcohols, ROH
33:14
Synthesis of Alcohols From Ketones and Aldehydes
33:15
Organometallic Reagents: Preparation
37:03
Grignard (RMgX)
37:04
Organolithium (Rli)
40:03
Organometallic Reagents: Reactions
41:45
Reactions of Organometallic Reagents
41:46
Organometallic Reagents: Reactions as Strong Nu:
46:40
Example 1: Reactions as Strong Nu:
46:41
Example 2: Reactions as Strong Nu:
48:57
Hydride Nu:
50:52
Hydride Nu:
50:53
Examples
53:34
Predict 1
53:35
Predict 2
54:45
Examples
56:43
Transform
56:44
Provide Starting Material
58:18
Alcohols, Part II

45m 35s

Intro
0:00
Oxidation Reactions
0:08
Oxidizing Agents: Jones, PCC, Swern
0:09
'Jones' Oxidation
0:43
Example 1: Predict Oxidation Reactions
2:29
Example 2: Predict Oxidation Reactions
3:00
Oxidation Reactions
4:11
Selective Oxidizing Agents (PCC and Swern)
4:12
PCC (Pyridiniym Chlorochromate)
5:10
Swern Oxidation
6:05
General [ox] Mechanism
8:32
General [ox] Mechanism
8:33
Oxidation of Alcohols
10:11
Example 1: Oxidation of Alcohols
10:12
Example 2: Oxidation of Alcohols
11:20
Example 3: Oxidation of Alcohols
11:46
Example
13:09
Predict: PCC Oxidation Reactions
13:10
Tosylation of Alcohols
15:22
Introduction to Tosylation of Alcohols
15:23
Example
21:08
Example: Tosylation of Alcohols
21:09
Reductions of Alcohols
23:39
Reductions of Alcohols via SN2 with Hydride
24:22
Reductions of Alcohols via Dehydration
27:12
Conversion of Alcohols to Alkyl Halides
30:12
Conversion of Alcohols to Alkyl Halides via Tosylate
30:13
Conversion of Alcohols to Alkyl Halides
31:17
Using HX
31:18
Mechanism
32:09
Conversion of Alcohols to Alkyl Halides
35:43
Reagents that Provide LG and Nu: in One 'Pot'
35:44
General Mechanisms
37:44
Example 1: General Mechanisms
37:45
Example 2: General Mechanisms
39:25
Example
41:04
Transformation of Alcohols
41:05
V. Ethers, Thiols, Thioethers, & Ketones
Ethers

1h 34m 45s

Intro
0:00
Ethers
0:11
Overview of Ethers
0:12
Boiling Points
1:37
Ethers
4:34
Water Solubility (Grams per 100mL H₂O)
4:35
Synthesis of Ethers
7:53
Williamson Ether Synthesis
7:54
Example: Synthesis of Ethers
9:23
Synthesis of Ethers
10:27
Example: Synthesis of Ethers
10:28
Intramolecular SN2
13:04
Planning an Ether Synthesis
14:45
Example 1: Planning an Ether Synthesis
14:46
Planning an Ether Synthesis
16:16
Example 2: Planning an Ether Synthesis
16:17
Planning an Ether Synthesis
22:04
Example 3: Synthesize Dipropyl Ether
22:05
Planning an Ether Synthesis
26:01
Example 4: Transform
26:02
Synthesis of Epoxides
30:05
Synthesis of Epoxides Via Williamson Ether Synthesis
30:06
Synthesis of Epoxides Via Oxidation
32:42
Reaction of Ethers
33:35
Reaction of Ethers
33:36
Reactions of Ethers with HBr or HI
34:44
Reactions of Ethers with HBr or HI
34:45
Mechanism
35:25
Epoxide Ring-Opening Reaction
39:25
Epoxide Ring-Opening Reaction
39:26
Example: Epoxide Ring-Opening Reaction
42:42
Acid-Catalyzed Epoxide Ring Opening
44:16
Acid-Catalyzed Epoxide Ring Opening Mechanism
44:17
Acid-Catalyzed Epoxide Ring Opening
50:13
Acid-Catalyzed Epoxide Ring Opening Mechanism
50:14
Catalyst Needed for Ring Opening
53:34
Catalyst Needed for Ring Opening
53:35
Stereochemistry of Epoxide Ring Opening
55:56
Stereochemistry: SN2 Mechanism
55:57
Acid or Base Mechanism?
58:30
Example
01:03
Transformation
01:04
Regiochemistry of Epoxide Ring Openings
05:29
Regiochemistry of Epoxide Ring Openings in Base
05:30
Regiochemistry of Epoxide Ring Openings in Acid
07:34
Example
10:26
Example 1: Epoxide Ring Openings in Base
10:27
Example 2: Epoxide Ring Openings in Acid
12:50
Reactions of Epoxides with Grignard and Hydride
15:35
Reactions of Epoxides with Grignard and Hydride
15:36
Example
21:47
Example: Ethers
21:50
Example
27:01
Example: Synthesize
27:02
Thiols and Thioethers

16m 50s

Intro
0:00
Thiols and Thioethers
0:10
Physical Properties
0:11
Reactions Can Be Oxidized
2:16
Acidity of Thiols
3:11
Thiols Are More Acidic Than Alcohols
3:12
Synthesis of Thioethers
6:44
Synthesis of Thioethers
6:45
Example
8:43
Example: Synthesize the Following Target Molecule
8:44
Example
14:18
Example: Predict
14:19
Ketones

2h 18m 12s

Intro
0:00
Aldehydes & Ketones
0:11
The Carbonyl: Resonance & Inductive
0:12
Reactivity
0:50
The Carbonyl
2:35
The Carbonyl
2:36
Carbonyl FG's
4:10
Preparation/Synthesis of Aldehydes & Ketones
6:18
Oxidation of Alcohols
6:19
Ozonolysis of Alkenes
7:16
Hydration of Alkynes
8:01
Reaction with Hydride Nu:
9:00
Reaction with Hydride Nu:
9:01
Reaction with Carbon Nu:
11:29
Carbanions: Acetylide
11:30
Carbanions: Cyanide
14:23
Reaction with Carbon Nu:
15:32
Organometallic Reagents (RMgX, Rli)
15:33
Retrosynthesis of Alcohols
17:04
Retrosynthesis of Alcohols
17:05
Example
19:30
Example: Transform
19:31
Example
22:57
Example: Transform
22:58
Example
28:19
Example: Transform
28:20
Example
33:36
Example: Transform
33:37
Wittig Reaction
37:39
Wittig Reaction: A Resonance-Stabilized Carbanion (Nu:)
37:40
Wittig Reaction: Mechanism
39:51
Preparation of Wittig Reagent
41:58
Two Steps From RX
41:59
Example: Predict
45:02
Wittig Retrosynthesis
46:19
Wittig Retrosynthesis
46:20
Synthesis
48:09
Reaction with Oxygen Nu:
51:21
Addition of H₂O
51:22
Exception: Formaldehyde is 99% Hydrate in H₂O Solution
54:10
Exception: Hydrate is Favored if Partial Positive Near Carbonyl
55:26
Reaction with Oxygen Nu:
57:45
Addition of ROH
57:46
TsOH: Tosic Acid
58:28
Addition of ROH Cont.
59:09
Example
01:43
Predict
01:44
Mechanism
03:08
Mechanism for Acetal Formation
04:10
Mechanism for Acetal Formation
04:11
What is a CTI?
15:04
Tetrahedral Intermediate
15:05
Charged Tetrahedral Intermediate
15:45
CTI: Acid-cat
16:10
CTI: Base-cat
17:01
Acetals & Cyclic Acetals
17:49
Overall
17:50
Cyclic Acetals
18:46
Hydrolysis of Acetals: Regenerates Carbonyl
20:01
Hydrolysis of Acetals: Regenerates Carbonyl
20:02
Mechanism
22:08
Reaction with Nitrogen Nu:
30:11
Reaction with Nitrogen Nu:
30:12
Example
32:18
Mechanism of Imine Formation
33:24
Mechanism of Imine Formation
33:25
Oxidation of Aldehydes
38:12
Oxidation of Aldehydes 1
38:13
Oxidation of Aldehydes 2
39:52
Oxidation of Aldehydes 3
40:10
Reductions of Ketones and Aldehydes
40:54
Reductions of Ketones and Aldehydes
40:55
Hydride/ Workup
41:22
Raney Nickel
42:07
Reductions of Ketones and Aldehydes
43:24
Clemmensen Reduction & Wolff-Kishner Reduction
43:40
Acetals as Protective Groups
46:50
Acetals as Protective Groups
46:51
Example
50:39
Example: Consider the Following Synthesis
50:40
Protective Groups
54:47
Protective Groups
54:48
Example
59:02
Example: Transform
59:03
Example: Another Route
04:54
Example: Transform
08:49
Example
08:50
Transform
08:51
Example
11:05
Transform
11:06
Example
13:45
Transform
13:46
Example
15:43
Provide the Missing Starting Material
15:44
VI. Organic Transformation Practice
Transformation Practice Problems

38m 58s

Intro
0:00
Practice Problems
0:33
Practice Problem 1: Transform
0:34
Practice Problem 2: Transform
3:57
Practice Problems
7:49
Practice Problem 3: Transform
7:50
Practice Problems
15:32
Practice Problem 4: Transform
15:34
Practice Problem 5: Transform
20:15
Practice Problems
24:08
Practice Problem 6: Transform
24:09
Practice Problem 7: Transform
29:27
Practice Problems
33:08
Practice Problem 8: Transform
33:09
Practice Problem 9: Transform
35:23
VII. Carboxylic Acids
Carboxylic Acids

1h 17m 51s

Intro
0:00
Review Reactions of Ketone/Aldehyde
0:06
Carbonyl Reactivity
0:07
Nu: = Hydride (Reduction)
1:37
Nu: = Grignard
2:08
Review Reactions of Ketone/Aldehyde
2:53
Nu: = Alcohol
2:54
Nu: = Amine
3:46
Carboxylic Acids and Their Derivatives
4:37
Carboxylic Acids and Their Derivatives
4:38
Ketone vs. Ester Reactivity
6:33
Ketone Reactivity
6:34
Ester Reactivity
6:55
Carboxylic Acids and Their Derivatives
7:30
Acid Halide, Anhydride, Ester, Amide, and Nitrile
7:43
General Reactions of Acarboxylic Acid Derivatives
9:22
General Reactions of Acarboxylic Acid Derivatives
9:23
Physical Properties of Carboxylic Acids
12:16
Acetic Acid
12:17
Carboxylic Acids
15:46
Aciditiy of Carboxylic Acids, RCO₂H
17:45
Alcohol
17:46
Carboxylic Acid
19:21
Aciditiy of Carboxylic Acids, RCO₂H
21:31
Aciditiy of Carboxylic Acids, RCO₂H
21:32
Aciditiy of Carboxylic Acids, RCO₂H
24:48
Example: Which is the Stronger Acid?
24:49
Aciditiy of Carboxylic Acids, RCO₂H
30:06
Inductive Effects Decrease with Distance
30:07
Preparation of Carboxylic Acids, RCO₂H
31:55
A) By Oxidation
31:56
Preparation of Carboxylic Acids, RCO₂H
34:37
Oxidation of Alkenes/Alkynes - Ozonolysis
34:38
Preparation of Carboxylic Acids, RCO₂H
36:17
B) Preparation of RCO₂H from Organometallic Reagents
36:18
Preparation of Carboxylic Acids, RCO₂H
38:02
Example: Preparation of Carboxylic Acids
38:03
Preparation of Carboxylic Acids, RCO₂H
40:38
C) Preparation of RCO₂H by Hydrolysis of Carboxylic Acid Derivatives
40:39
Hydrolysis Mechanism
42:19
Hydrolysis Mechanism
42:20
Mechanism: Acyl Substitution (Addition/Elimination)
43:05
Hydrolysis Mechanism
47:27
Substitution Reaction
47:28
RO is Bad LG for SN1/SN2
47:39
RO is okay LG for Collapse of CTI
48:31
Hydrolysis Mechanism
50:07
Base-promoted Ester Hydrolysis (Saponification)
50:08
Applications of Carboxylic Acid Derivatives:
53:10
Saponification Reaction
53:11
Ester Hydrolysis
57:15
Acid-Catalyzed Mechanism
57:16
Ester Hydrolysis Requires Acide or Base
03:06
Ester Hydrolysis Requires Acide or Base
03:07
Nitrile Hydrolysis
05:22
Nitrile Hydrolysis
05:23
Nitrile Hydrolysis Mechanism
06:53
Nitrile Hydrolysis Mechanism
06:54
Use of Nitriles in Synthesis
12:39
Example: Nitirles in Synthesis
12:40
Carboxylic Acid Derivatives

1h 21m 4s

Intro
0:00
Carboxylic Acid Derivatives
0:05
Carboxylic Acid Derivatives
0:06
General Structure
1:00
Preparation of Carboxylic Acid Derivatives
1:19
Which Carbonyl is the Better E+?
1:20
Inductive Effects
1:54
Resonance
3:23
Preparation of Carboxylic Acid Derivatives
6:52
Which is Better E+, Ester or Acid Chloride?
6:53
Inductive Effects
7:02
Resonance
7:20
Preparation of Carboxylic Acid Derivatives
10:45
Which is Better E+, Carboxylic Acid or Anhydride?
10:46
Inductive Effects & Resonance
11:00
Overall: Order of Electrophilicity and Leaving Group
14:49
Order of Electrophilicity and Leaving Group
14:50
Example: Acid Chloride
16:26
Example: Carboxylate
19:17
Carboxylic Acid Derivative Interconversion
20:53
Carboxylic Acid Derivative Interconversion
20:54
Preparation of Acid Halides
24:31
Preparation of Acid Halides
24:32
Preparation of Anhydrides
25:45
A) Dehydration of Acids (For Symmetrical Anhydride)
25:46
Preparation of Anhydrides
27:29
Example: Dehydration of Acids
27:30
Preparation of Anhydrides
29:16
B) From an Acid Chloride (To Make Mixed Anhydride)
29:17
Mechanism
30:03
Preparation of Esters
31:53
A) From Acid Chloride or Anhydride
31:54
Preparation of Esters
33:48
B) From Carboxylic Acids (Fischer Esterification)
33:49
Mechanism
36:55
Preparations of Esters
41:38
Example: Predict the Product
41:39
Preparation of Esters
43:17
C) Transesterification
43:18
Mechanism
45:17
Preparation of Esters
47:58
D) SN2 with Carboxylate
47:59
Mechanism: Diazomethane
49:28
Preparation of Esters
51:01
Example: Transform
51:02
Preparation of Amides
52:27
A) From an Acid Cl or Anhydride
52:28
Preparations of Amides
54:47
B) Partial Hydrolysis of Nitriles
54:48
Preparation of Amides
56:11
Preparation of Amides: Find Alternate Path
56:12
Preparation of Amides
59:04
C) Can't be Easily Prepared from RCO₂H Directly
59:05
Reactions of Carboxylic Acid Derivatives with Nucleophiles
01:41
A) Hydride Nu: Review
01:42
A) Hydride Nu: Sodium Borohydride + Ester
02:43
Reactions of Carboxylic Acid Derivatives with Nucleophiles
03:57
Lithium Aluminum Hydride (LAH)
03:58
Mechanism
04:29
Summary of Hydride Reductions
07:09
Summary of Hydride Reductions 1
07:10
Summary of Hydride Reductions 2
07:36
Hydride Reduction of Amides
08:12
Hydride Reduction of Amides Mechanism
08:13
Reaction of Carboxylic Acid Derivatives with Organometallics
12:04
Review 1
12:05
Review 2
12:50
Reaction of Carboxylic Acid Derivatives with Organometallics
14:22
Example: Lactone
14:23
Special Hydride Nu: Reagents
16:34
Diisobutylaluminum Hydride
16:35
Example
17:25
Other Special Hydride
18:41
Addition of Organocuprates to Acid Chlorides
19:07
Addition of Organocuprates to Acid Chlorides
19:08
VIII. Enols & Enolates
Enols and Enolates, Part 1

1h 26m 22s

Intro
0:00
Enols and Enolates
0:09
The Carbonyl
0:10
Keto-Enol Tautomerization
1:17
Keto-Enol Tautomerization Mechanism
2:28
Tautomerization Mechanism (2 Steps)
2:29
Keto-Enol Tautomerization Mechanism
5:15
Reverse Reaction
5:16
Mechanism
6:07
Formation of Enolates
7:27
Why is a Ketone's α H's Acidic?
7:28
Formation of Other Carbanions
10:05
Alkyne
10:06
Alkane and Alkene
10:53
Formation of an Enolate: Choice of Base
11:27
Example: Choice of Base
11:28
Formation of an Enolate: Choice of Base
13:56
Deprotonate, Stronger Base, and Lithium Diisopropyl Amide (LDA)
13:57
Formation of an Enolate: Choice of Base
15:48
Weaker Base & 'Active' Methylenes
15:49
Why Use NaOEt instead of NaOH?
19:01
Other Acidic 'α' Protons
20:30
Other Acidic 'α' Protons
20:31
Why is an Ester Less Acidic than a Ketone?
24:10
Other Acidic 'α' Protons
25:19
Other Acidic 'α' Protons Continue
25:20
How are Enolates Used
25:54
Enolates
25:55
Possible Electrophiles
26:21
Alkylation of Enolates
27:56
Alkylation of Enolates
27:57
Resonance Form
30:03
α-Halogenation
32:17
α-Halogenation
32:18
Iodoform Test for Methyl Ketones
33:47
α-Halogenation
35:55
Acid-Catalyzed
35:57
Mechanism: 1st Make Enol (2 Steps)
36:14
Whate Other Eloctrophiles ?
39:17
Aldol Condensation
39:38
Aldol Condensation
39:39
Aldol Mechanism
41:26
Aldol Mechanism: In Base, Deprotonate First
41:27
Aldol Mechanism
45:28
Mechanism for Loss of H₂O
45:29
Collapse of CTI and β-elimination Mechanism
47:51
Loss of H₂0 is not E2!
48:39
Aldol Summary
49:53
Aldol Summary
49:54
Base-Catalyzed Mechanism
52:34
Acid-Catalyzed Mechansim
53:01
Acid-Catalyzed Aldol Mechanism
54:01
First Step: Make Enol
54:02
Acid-Catalyzed Aldol Mechanism
56:54
Loss of H₂0 (β elimination)
56:55
Crossed/Mixed Aldol
00:55
Crossed/Mixed Aldol & Compound with α H's
00:56
Ketone vs. Aldehyde
02:30
Crossed/Mixed Aldol & Compound with α H's Continue
03:10
Crossed/Mixed Aldol
05:21
Mixed Aldol: control Using LDA
05:22
Crossed/Mixed Aldol Retrosynthesis
08:53
Example: Predic Aldol Starting Material (Aldol Retrosyntheiss)
08:54
Claisen Condensation
12:54
Claisen Condensation (Aldol on Esters)
12:55
Claisen Condensation
19:52
Example 1: Claisen Condensation
19:53
Claisen Condensation
22:48
Example 2: Claisen Condensation
22:49
Enols and Enolates, Part 2

50m 57s

Intro
0:00
Conjugate Additions
0:06
α, β-unsaturated Carbonyls
0:07
Conjugate Additions
1:50
'1,2-addition'
1:51
'1,-4-addition' or 'Conjugate Addition'
2:24
Conjugate Additions
4:53
Why can a Nu: Add to this Alkene?
4:54
Typical Alkene
5:09
α, β-unsaturated Alkene
5:39
Electrophilic Alkenes: Michael Acceptors
6:35
Other 'Electrophilic' Alkenes (Called 'Michael Acceptors)
6:36
1,4-Addition of Cuprates (R2CuLi)
8:29
1,4-Addition of Cuprates (R2CuLi)
8:30
1,4-Addition of Cuprates (R2CuLi)
11:23
Use Cuprates in Synthesis
11:24
Preparation of Cuprates
12:25
Prepare Organocuprate From Organolithium
12:26
Cuprates Also Do SN2 with RX E+ (Not True for RMgX, RLi)
13:06
1,4-Addition of Enolates: Michael Reaction
13:50
1,4-Addition of Enolates: Michael Reaction
13:51
Mechanism
15:57
1,4-Addition of Enolates: Michael Reaction
18:47
Example: 1,4-Addition of Enolates
18:48
1,4-Addition of Enolates: Michael Reaction
21:02
Michael Reaction, Followed by Intramolecular Aldol
21:03
Mechanism of the Robinson Annulation
24:26
Mechanism of the Robinson Annulation
24:27
Enols and Enolates: Advanced Synthesis Topics
31:10
Stablized Enolates and the Decarboxylation Reaction
31:11
Mechanism: A Pericyclic Reaction
32:08
Enols and Enolates: Advanced Synthesis Topics
33:32
Example: Advance Synthesis
33:33
Enols and Enolates: Advanced Synthesis Topics
36:10
Common Reagents: Diethyl Malonate
36:11
Common Reagents: Ethyl Acetoacetate
37:27
Enols and Enolates: Advanced Synthesis Topics
38:06
Example: Transform
38:07
Advanced Synthesis Topics: Enamines
41:52
Enamines
41:53
Advanced Synthesis Topics: Enamines
43:06
Reaction with Ketone/Aldehyde
43:07
Example
44:08
Advanced Synthesis Topics: Enamines
45:31
Example: Use Enamines as Nu: (Like Enolate)
45:32
Advanced Synthesis Topics: Enamines
47:56
Example
47:58
IX. Aromatic Compounds
Aromatic Compounds: Structure

1h 59s

Intro
0:00
Aromatic Compounds
0:05
Benzene
0:06
3D Sketch
1:33
Features of Benzene
4:41
Features of Benzene
4:42
Aromatic Stability
6:41
Resonance Stabilization of Benzene
6:42
Cyclohexatriene
7:24
Benzene (Actual, Experimental)
8:11
Aromatic Stability
9:03
Energy Graph
9:04
Aromaticity Requirements
9:55
1) Cyclic and Planar
9:56
2) Contiguous p Orbitals
10:49
3) Satisfy Huckel's Rule
11:20
Example: Benzene
12:32
Common Aromatic Compounds
13:28
Example: Pyridine
13:29
Common Aromatic Compounds
16:25
Example: Furan
16:26
Common Aromatic Compounds
19:42
Example: Thiophene
19:43
Example: Pyrrole
20:18
Common Aromatic Compounds
21:09
Cyclopentadienyl Anion
21:10
Cycloheptatrienyl Cation
23:48
Naphthalene
26:04
Determining Aromaticity
27:28
Example: Which of the Following are Aromatic?
27:29
Molecular Orbital (MO) Theory
32:26
What's So Special About '4n + 2' Electrons?
32:27
π bond & Overlapping p Orbitals
32:53
Molecular Orbital (MO) Diagrams
36:56
MO Diagram: Benzene
36:58
Drawing MO Diagrams
44:26
Example: 3-Membered Ring
44:27
Example: 4-Membered Ring
46:04
Drawing MO Diagrams
47:51
Example: 5-Membered Ring
47:52
Example: 8-Membered Ring
49:32
Aromaticity and Reactivity
51:03
Example: Which is More Acidic?
51:04
Aromaticity and Reactivity
56:03
Example: Which has More Basic Nitrogen, Pyrrole or Pyridine?
56:04
Aromatic Compounds: Reactions, Part 1

1h 24m 4s

Intro
0:00
Reactions of Benzene
0:07
N/R as Alkenes
0:08
Substitution Reactions
0:50
Electrophilic Aromatic Substitution
1:24
Electrophilic Aromatic Substitution
1:25
Mechanism Step 1: Addition of Electrophile
2:08
Mechanism Step 2: Loss of H+
4:14
Electrophilic Aromatic Substitution on Substituted Benzenes
5:21
Electron Donating Group
5:22
Electron Withdrawing Group
8:02
Halogen
9:23
Effects of Electron-Donating Groups (EDG)
10:23
Effects of Electron-Donating Groups (EDG)
10:24
What Effect Does EDG (OH) Have?
11:40
Reactivity
13:03
Regioselectivity
14:07
Regioselectivity: EDG is o/p Director
14:57
Prove It! Add E+ and Look at Possible Intermediates
14:58
Is OH Good or Bad?
17:38
Effects of Electron-Withdrawing Groups (EWG)
20:20
What Effect Does EWG Have?
20:21
Reactivity
21:28
Regioselectivity
22:24
Regioselectivity: EWG is a Meta Director
23:23
Prove It! Add E+ and Look at Competing Intermediates
23:24
Carbocation: Good or Bad?
26:01
Effects of Halogens on EAS
28:33
Inductive Withdrawal of e- Density vs. Resonance Donation
28:34
Summary of Substituent Effects on EAS
32:33
Electron Donating Group
32:34
Electron Withdrawing Group
33:37
Directing Power of Substituents
34:35
Directing Power of Substituents
34:36
Example
36:41
Electrophiles for Electrophilic Aromatic Substitution
38:43
Reaction: Halogenation
38:44
Electrophiles for Electrophilic Aromatic Substitution
40:27
Reaction: Nitration
40:28
Electrophiles for Electrophilic Aromatic Substitution
41:45
Reaction: Sulfonation
41:46
Electrophiles for Electrophilic Aromatic Substitution
43:19
Reaction: Friedel-Crafts Alkylation
43:20
Electrophiles for Electrophilic Aromatic Substitution
45:43
Reaction: Friedel-Crafts Acylation
45:44
Electrophilic Aromatic Substitution: Nitration
46:52
Electrophilic Aromatic Substitution: Nitration
46:53
Mechanism
48:56
Nitration of Aniline
52:40
Nitration of Aniline Part 1
52:41
Nitration of Aniline Part 2: Why?
54:12
Nitration of Aniline
56:10
Workaround: Protect Amino Group as an Amide
56:11
Electrophilic Aromatic Substitution: Sulfonation
58:16
Electrophilic Aromatic Substitution: Sulfonation
58:17
Example: Transform
59:25
Electrophilic Aromatic Substitution: Friedel-Crafts Alkylation
02:24
Electrophilic Aromatic Substitution: Friedel-Crafts Alkylation
02:25
Example & Mechanism
03:37
Friedel-Crafts Alkylation Drawbacks
05:48
A) Can Over-React (Dialkylation)
05:49
Friedel-Crafts Alkylation Drawbacks
08:21
B) Carbocation Can Rearrange
08:22
Mechanism
09:33
Friedel-Crafts Alkylation Drawbacks
13:35
Want n-Propyl? Use Friedel-Crafts Acylation
13:36
Reducing Agents
16:45
Synthesis with Electrophilic Aromatic Substitution
18:45
Example: Transform
18:46
Synthesis with Electrophilic Aromatic Substitution
20:59
Example: Transform
21:00
Aromatic Compounds: Reactions, Part 2

59m 10s

Intro
0:00
Reagents for Electrophilic Aromatic Substitution
0:07
Reagents for Electrophilic Aromatic Substitution
0:08
Preparation of Diazonium Salt
2:12
Preparation of Diazonium Salt
2:13
Reagents for Sandmeyer Reactions
4:14
Reagents for Sandmeyer Reactions
4:15
Apply Diazonium Salt in Synthesis
6:20
Example: Transform
6:21
Apply Diazonium Salt in Synthesis
9:14
Example: Synthesize Following Target Molecule from Benzene or Toluene
9:15
Apply Diazonium Salt in Synthesis
14:56
Example: Transform
14:57
Reactions of Aromatic Substituents
21:56
A) Reduction Reactions
21:57
Reactions of Aromatic Substituents
23:24
B) Oxidations of Arenes
23:25
Benzylic [ox] Even Breaks C-C Bonds!
25:05
Benzylic Carbon Can't Be Quaternary
25:55
Reactions of Aromatic Substituents
26:21
Example
26:22
Review of Benzoic Acid Synthesis
27:34
Via Hydrolysis
27:35
Via Grignard
28:20
Reactions of Aromatic Substituents
29:15
C) Benzylic Halogenation
29:16
Radical Stabilities
31:55
N-bromosuccinimide (NBS)
32:23
Reactions of Aromatic Substituents
33:08
D) Benzylic Substitutions
33:09
Reactions of Aromatic Side Chains
37:08
Example: Transform
37:09
Nucleophilic Aromatic Substitution
43:13
Nucleophilic Aromatic Substitution
43:14
Nucleophilic Aromatic Substitution
47:08
Example
47:09
Mechanism
48:00
Nucleophilic Aromatic Substitution
50:43
Example
50:44
Nucleophilic Substitution: Benzyne Mechanism
52:46
Nucleophilic Substitution: Benzyne Mechanism
52:47
Nucleophilic Substitution: Benzyne Mechanism
57:31
Example: Predict Product
57:32
X. Dienes & Amines
Conjugated Dienes

1h 9m 12s

Intro
0:00
Conjugated Dienes
0:08
Conjugated π Bonds
0:09
Diene Stability
2:00
Diene Stability: Cumulated
2:01
Diene Stability: Isolated
2:37
Diene Stability: Conjugated
2:51
Heat of Hydrogenation
3:00
Allylic Carbocations and Radicals
5:15
Allylic Carbocations and Radicals
5:16
Electrophilic Additions to Dienes
7:00
Alkenes
7:01
Unsaturated Ketone
7:47
Electrophilic Additions to Dienes
8:28
Conjugated Dienes
8:29
Electrophilic Additions to Dienes
9:46
Mechanism (2-Steps): Alkene
9:47
Electrophilic Additions to Dienes
11:40
Mechanism (2-Steps): Diene
11:41
1,2 'Kinetic' Product
13:08
1,4 'Thermodynamic' Product
14:47
E vs. POR Diagram
15:50
E vs. POR Diagram
15:51
Kinetic vs. Thermodynamic Control
21:56
Kinetic vs. Thermodynamic Control
21:57
How? Reaction is Reversible!
23:51
1,2 (Less Stable product)
23:52
1,4 (More Stable Product)
25:16
Diels Alder Reaction
26:34
Diels Alder Reaction
26:35
Dienophiles (E+)
29:23
Dienophiles (E+)
29:24
Alkyne Diels-Alder Example
30:48
Example: Alkyne Diels-Alder
30:49
Diels-Alder Reaction: Dienes (Nu:)
32:22
Diels-Alder ReactionL Dienes (Nu:)
32:23
Diels-Alder Reaction: Dienes
33:51
Dienes Must Have 's-cis' Conformation
33:52
Example
35:25
Diels-Alder Reaction with Cyclic Dienes
36:08
Cyclic Dienes are Great for Diels-Alder Reaction
36:09
Cyclopentadiene
37:10
Diels-Alder Reaction: Bicyclic Products
40:50
Endo vs. Exo Terminology: Norbornane & Bicyclo Heptane
40:51
Example: Bicyclo Heptane
42:29
Diels-Alder Reaction with Cyclic Dienes
44:15
Example
44:16
Stereochemistry of the Diels-Alder Reaction
47:39
Stereochemistry of the Diels-Alder Reaction
47:40
Example
48:08
Stereochemistry of the Diels-Alder Reaction
50:21
Example
50:22
Regiochemistry of the Diels-Alder Reaction
52:42
Rule: 1,2-Product Preferred Over 1,3-Product
52:43
Regiochemistry of the Diels-Alder Reaction
54:18
Rule: 1,4-Product Preferred Over 1,3-Product
54:19
Regiochemistry of the Diels-Alder Reaction
55:02
Why 1,2-Product or 1,4-Product Favored?
55:03
Example
56:11
Diels-Alder Reaction
58:06
Example: Predict
58:07
Diels-Alder Reaction
01:27
Explain Why No Diels-Alder Reaction Takes Place in This Case
01:28
Diels-Alder Reaction
03:09
Example: Predict
03:10
Diels-Alder Reaction: Synthesis Problem
05:39
Diels-Alder Reaction: Synthesis Problem
05:40
Pericyclic Reactions and Molecular Orbital (MO) Theory

1h 21m 31s

Intro
0:00
Pericyclic Reactions
0:05
Pericyclic Reactions
0:06
Electrocyclic Reactions
1:19
Electrocyclic Reactions
1:20
Electrocyclic Reactions
3:13
Stereoselectivity
3:14
Electrocyclic Reactions
8:10
Example: Predict
8:11
Sigmatropic Rearrangements
12:29
Sigmatropic Rearrangements
12:30
Cope Rearrangement
14:44
Sigmatropic Rearrangements
16:44
Claisen Rearrangement 1
16:45
Claisen Rearrangement 2
17:46
Cycloaddition Reactions
19:22
Diels-Alder
19:23
1,3-Dipolar Cycloaddition
20:32
Cycloaddition Reactions: Stereochemistry
21:58
Cycloaddition Reactions: Stereochemistry
21:59
Cycloaddition Reactions: Heat or Light?
26:00
4+2 Cycloadditions
26:01
2+2 Cycloadditions
27:23
Molecular Orbital (MO) Theory of Chemical Reactions
29:26
Example 1: Molecular Orbital Theory of Bonding
29:27
Molecular Orbital (MO) Theory of Chemical Reactions
31:59
Example 2: Molecular Orbital Theory of Bonding
32:00
Molecular Orbital (MO) Theory of Chemical Reactions
33:33
MO Theory of Aromaticity, Huckel's Rule
33:34
Molecular Orbital (MO) Theory of Chemical Reactions
36:43
Review: Molecular Orbital Theory of Conjugated Systems
36:44
Molecular Orbital (MO) Theory of Chemical Reactions
44:56
Review: Molecular Orbital Theory of Conjugated Systems
44:57
Molecular Orbital (MO) Theory of Chemical Reactions
46:54
Review: Molecular Orbital Theory of Conjugated Systems
46:55
Molecular Orbital (MO) Theory of Chemical Reactions
48:36
Frontier Molecular Orbitals are Involved in Reactions
48:37
Examples
50:20
MO Theory of Pericyclic Reactions: The Woodward-Hoffmann Rules
51:51
Heat-promoted Pericyclic Reactions and Light-promoted Pericyclic Reactions
51:52
MO Theory of Pericyclic Reactions: The Woodward-Hoffmann Rules
53:42
Why is a [4+2] Cycloaddition Thermally Allowed While the [2+2] is Not?
53:43
MO Theory of Pericyclic Reactions: The Woodward-Hoffmann Rules
56:51
Why is a [2+2] Cycloaddition Photochemically Allowed?
56:52
Pericyclic Reaction Example I
59:16
Pericyclic Reaction Example I
59:17
Pericyclic Reaction Example II
07:40
Pericyclic Reaction Example II
07:41
Pericyclic Reaction Example III: Vitamin D - The Sunshine Vitamin
14:22
Pericyclic Reaction Example III: Vitamin D - The Sunshine Vitamin
14:23
Amines

34m 58s

Intro
0:00
Amines: Properties and Reactivity
0:04
Compare Amines to Alcohols
0:05
Amines: Lower Boiling Point than ROH
0:55
1) RNH₂ Has Lower Boiling Point than ROH
0:56
Amines: Better Nu: Than ROH
2:22
2) RNH₂ is a Better Nucleophile than ROH Example 1
2:23
RNH₂ is a Better Nucleophile than ROH Example 2
3:08
Amines: Better Nu: than ROH
3:47
Example
3:48
Amines are Good Bases
5:41
3) RNH₂ is a Good Base
5:42
Amines are Good Bases
7:06
Example 1
7:07
Example 2: Amino Acid
8:27
Alkyl vs. Aryl Amines
9:56
Example: Which is Strongest Base?
9:57
Alkyl vs. Aryl Amines
14:55
Verify by Comparing Conjugate Acids
14:56
Reaction of Amines
17:42
Reaction with Ketone/Aldehyde: 1° Amine (RNH₂)
17:43
Reaction of Amines
18:48
Reaction with Ketone/Aldehyde: 2° Amine (R2NH)
18:49
Use of Enamine: Synthetic Equivalent of Enolate
20:08
Use of Enamine: Synthetic Equivalent of Enolate
20:09
Reaction of Amines
24:10
Hofmann Elimination
24:11
Hofmann Elimination
26:16
Kinetic Product
26:17
Structure Analysis Using Hofmann Elimination
28:22
Structure Analysis Using Hofmann Elimination
28:23
Biological Activity of Amines
30:30
Adrenaline
31:07
Mescaline (Peyote Alkaloid)
31:22
Amino Acids, Amide, and Protein
32:14
Biological Activity of Amines
32:50
Morphine (Opium Alkaloid)
32:51
Epibatidine (Poison Dart Frog)
33:28
Nicotine
33:48
Choline (Nerve Impulse)
34:03
XI. Biomolecules & Polymers
Biomolecules

1h 53m 20s

Intro
0:00
Carbohydrates
1:11
D-glucose Overview
1:12
D-glucose: Cyclic Form (6-membered ring)
4:31
Cyclic Forms of Glucose: 6-membered Ring
8:24
α-D-glucopyranose & β-D-glucopyranose
8:25
Formation of a 5-Membered Ring
11:05
D-glucose: Formation of a 5-Membered Ring
11:06
Cyclic Forms of Glucose: 5-membered Ring
12:37
α-D-glucofuranose & β-D-glucofuranose
12:38
Carbohydrate Mechanism
14:03
Carbohydrate Mechanism
14:04
Reactions of Glucose: Acetal Formation
21:35
Acetal Formation: Methyl-α-D-glucoside
21:36
Hemiacetal to Acetal: Overview
24:58
Mechanism for Formation of Glycosidic Bond
25:51
Hemiacetal to Acetal: Mechanism
25:52
Formation of Disaccharides
29:34
Formation of Disaccharides
29:35
Some Polysaccharides: Starch
31:33
Amylose & Amylopectin
31:34
Starch: α-1,4-glycosidic Bonds
32:22
Properties of Starch Molecule
33:21
Some Polysaccharides: Cellulose
33:59
Cellulose: β-1,4-glycosidic bonds
34:00
Properties of Cellulose
34:59
Other Sugar-Containing Biomolecules
35:50
Ribonucleoside (RNA)
35:51
Deoxyribonucleoside (DMA)
36:59
Amino Acids & Proteins
37:32
α-amino Acids: Structure & Stereochemistry
37:33
Making a Protein (Condensation)
42:46
Making a Protein (Condensation)
42:47
Peptide Bond is Planar (Amide Resonance)
44:55
Peptide Bond is Planar (Amide Resonance)
44:56
Protein Functions
47:49
Muscle, Skin, Bones, Hair Nails
47:50
Enzymes
49:10
Antibodies
49:44
Hormones, Hemoglobin
49:58
Gene Regulation
50:20
Various Amino Acid Side Chains
50:51
Nonpolar
50:52
Polar
51:15
Acidic
51:24
Basic
51:55
Amino Acid Table
52:22
Amino Acid Table
52:23
Isoelectric Point (pI)
53:43
Isoelectric Point (pI) of Glycine
53:44
Isoelectric Point (pI) of Glycine: pH 11
56:42
Isoelectric Point (pI) of Glycine: pH 1
57:20
Isoelectric Point (pI), cont.
58:05
Asparatic Acid
58:06
Histidine
00:28
Isoelectric Point (pI), cont.
02:54
Example: What is the Net Charge of This Tetrapeptide at pH 6.0?
02:55
Nucleic Acids: Ribonucleosides
10:32
Nucleic Acids: Ribonucleosides
10:33
Nucleic Acids: Ribonucleotides
11:48
Ribonucleotides: 5' Phosphorylated Ribonucleosides
11:49
Ribonucleic Acid (RNA) Structure
12:35
Ribonucleic Acid (RNA) Structure
12:36
Nucleic Acids: Deoxyribonucleosides
14:08
Nucleic Acids: Deoxyribonucleosides
14:09
Deoxythymidine (T)
14:36
Nucleic Acids: Base-Pairing
15:17
Nucleic Acids: Base-Pairing
15:18
Double-Stranded Structure of DNA
18:16
Double-Stranded Structure of DNA
18:17
Model of DNA
19:40
Model of DNA
19:41
Space-Filling Model of DNA
20:46
Space-Filling Model of DNA
20:47
Function of RNA and DNA
23:06
DNA & Transcription
23:07
RNA & Translation
24:22
Genetic Code
25:09
Genetic Code
25:10
Lipids/Fats/Triglycerides
27:10
Structure of Glycerol
27:43
Saturated & Unsaturated Fatty Acids
27:51
Triglyceride
28:43
Unsaturated Fats: Lower Melting Points (Liquids/Oils)
29:15
Saturated Fat
29:16
Unsaturated Fat
30:10
Partial Hydrogenation
32:05
Saponification of Fats
35:11
Saponification of Fats
35:12
History of Soap
36:50
Carboxylate Salts form Micelles in Water
41:02
Carboxylate Salts form Micelles in Water
41:03
Cleaning Power of Micelles
42:21
Cleaning Power of Micelles
42:22
3-D Image of a Micelle
42:58
3-D Image of a Micelle
42:59
Synthesis of Biodiesel
44:04
Synthesis of Biodiesel
44:05
Phosphoglycerides
47:54
Phosphoglycerides
47:55
Cell Membranes Contain Lipid Bilayers
48:41
Cell Membranes Contain Lipid Bilayers
48:42
Bilayer Acts as Barrier to Movement In/Out of Cell
50:24
Bilayer Acts as Barrier to Movement In/Out of Cell
50:25
Organic Chemistry Meets Biology… Biochemistry!
51:12
Organic Chemistry Meets Biology… Biochemistry!
51:13
Polymers

45m 47s

Intro
0:00
Polymers
0:05
Monomer to Polymer: Vinyl Chloride to Polyvinyl Chloride
0:06
Polymer Properties
1:32
Polymer Properties
1:33
Natural Polymers: Rubber
2:30
Vulcanization
2:31
Natural Polymers: Polysaccharides
4:55
Example: Starch
4:56
Example: Cellulose
5:45
Natural Polymers: Proteins
6:07
Example: Keratin
6:08
DNA Strands
7:15
DNA Strands
7:16
Synthetic Polymers
8:30
Ethylene & Polyethylene: Lightweight Insulator & Airtight Plastic
8:31
Synthetic Organic Polymers
12:22
Polyethylene
12:28
Polyvinyl Chloride (PVC)
12:54
Polystyrene
13:28
Polyamide
14:34
Polymethyl Methacrylate
14:57
Kevlar
15:25
Synthetic Material Examples
16:30
How are Polymers Made?
21:00
Chain-growth Polymers Additions to Alkenes can be Radical, Cationic or Anionic
21:01
Chain Branching
22:34
Chain Branching
22:35
Special Reaction Conditions Prevent Branching
24:28
Ziegler-Natta Catalyst
24:29
Chain-Growth by Cationic Polymerization
27:35
Chain-Growth by Cationic Polymerization
27:36
Chain-Growth by Anionic Polymerization
29:35
Chain-Growth by Anionic Polymerization
29:36
Step-Growth Polymerization: Polyamides
32:16
Step-Growth Polymerization: Polyamides
32:17
Step-Growth Polymerization: Polyesters
34:23
Step-Growth Polymerization: Polyesters
34:24
Step-Growth Polymerization: Polycarbonates
35:56
Step-Growth Polymerization: Polycarbonates
35:57
Step-Growth Polymerization: Polyurethanes
37:18
Step-Growth Polymerization: Polyurethanes
37:19
Modifying Polymer Properties
39:35
Glass Transition Temperature
40:04
Crosslinking
40:42
Copolymers
40:58
Additives: Stabilizers
42:08
Additives: Flame Retardants
43:03
Additives: Plasticizers
43:41
Additives: Colorants
44:54
XII. Organic Synthesis
Organic Synthesis Strategies

2h 20m 24s

Intro
0:00
Organic Synthesis Strategies
0:15
Goal
0:16
Strategy
0:29
Example of a RetroSynthesis
1:30
Finding Starting Materials for Target Molecule
1:31
Synthesis Using Starting Materials
4:56
Synthesis of Alcohols by Functional Group Interconversion (FGI)
6:00
Synthesis of Alcohols by Functional Group Interconversion Overview
6:01
Alcohols by Reduction
7:43
Ketone to Alcohols
7:45
Aldehyde to Alcohols
8:26
Carboxylic Acid Derivative to Alcohols
8:36
Alcohols by Hydration of Alkenes
9:28
Hydration of Alkenes Using H₃O⁺
9:29
Oxymercuration-Demercuration
10:35
Hydroboration Oxidation
11:02
Alcohols by Substitution
11:42
Primary Alkyl Halide to Alcohols Using NaOH
11:43
Secondary Alkyl Halide to Alcohols Using Sodium Acetate
13:07
Tertiary Alkyl Halide to Alcohols Using H₂O
15:08
Synthesis of Alcohols by Forming a New C-C Bond
15:47
Recall: Alcohol & RMgBr
15:48
Retrosynthesis
17:28
Other Alcohol Disconnections
19:46
19:47
Synthesis Using PhMGgBr: Example 2
23:05
Synthesis of Alkyl Halides
26:06
Synthesis of Alkyl Halides Overview
26:07
Synthesis of Alkyl Halides by Free Radical Halogenation
27:04
Synthesis of Alkyl Halides by Free Radical Halogenation
27:05
Synthesis of Alkyl Halides by Substitution
29:06
Alcohol to Alkyl Halides Using HBr or HCl
29:07
Alcohol to Alkyl Halides Using SOCl₂
30:57
Alcohol to Alkyl Halides Using PBr₃ and Using P, I₂
31:03
Synthesis of Alkyl Halides by Addition
32:02
Alkene to Alkyl Halides Using HBr
32:03
Alkene to Alkyl Halides Using HBr & ROOR (Peroxides)
32:35
Example: Synthesis of Alkyl Halide
34:18
Example: Synthesis of Alkyl Halide
34:19
Synthesis of Ethers
39:25
Synthesis of Ethers
39:26
Example: Synthesis of an Ether
41:12
Synthesize TBME (t-butyl methyl ether) from Alcohol Starting Materials
41:13
Synthesis of Amines
46:05
Synthesis of Amines
46:06
Gabriel Synthesis of Amines
47:57
Gabriel Synthesis of Amines
47:58
Amines by SN2 with Azide Nu:
49:50
Amines by SN2 with Azide Nu:
49:51
Amines by SN2 with Cyanide Nu:
50:31
Amines by SN2 with Cyanide Nu:
50:32
Amines by Reduction of Amides
51:30
Amines by Reduction of Amides
51:31
Reductive Amination of Ketones/Aldehydes
52:42
Reductive Amination of Ketones/Aldehydes
52:43
Example : Synthesis of an Amine
53:47
Example 1: Synthesis of an Amine
53:48
Example 2: Synthesis of an Amine
56:16
Synthesis of Alkenes
58:20
Synthesis of Alkenes Overview
58:21
Synthesis of Alkenes by Elimination
59:04
Synthesis of Alkenes by Elimination Using NaOH & Heat
59:05
Synthesis of Alkenes by Elimination Using H₂SO₄ & Heat
59:57
Synthesis of Alkenes by Reduction
02:05
Alkyne to Cis Alkene
02:06
Alkyne to Trans Alkene
02:56
Synthesis of Alkenes by Wittig Reaction
03:46
Synthesis of Alkenes by Wittig Reaction
03:47
Retrosynthesis of an Alkene
05:35
Example: Synthesis of an Alkene
06:57
Example: Synthesis of an Alkene
06:58
Making a Wittig Reagent
10:31
Synthesis of Alkynes
13:09
Synthesis of Alkynes
13:10
Synthesis of Alkynes by Elimination (FGI)
13:42
First Step: Bromination of Alkene
13:43
Second Step: KOH Heat
14:22
Synthesis of Alkynes by Alkylation
15:02
Synthesis of Alkynes by Alkylation
15:03
Retrosynthesis of an Alkyne
16:18
Example: Synthesis of an Alkyne
17:40
Example: Synthesis of an Alkyne
17:41
Synthesis of Alkanes
20:52
Synthesis of Alkanes
20:53
Synthesis of Aldehydes & Ketones
21:38
Oxidation of Alcohol Using PCC or Swern
21:39
Oxidation of Alkene Using 1) O₃, 2)Zn
22:42
Reduction of Acid Chloride & Nitrile Using DiBAL-H
23:25
Hydration of Alkynes
24:55
Synthesis of Ketones by Acyl Substitution
26:12
Reaction with R'₂CuLi
26:13
Reaction with R'MgBr
27:13
Synthesis of Aldehydes & Ketones by α-Alkylation
28:00
Synthesis of Aldehydes & Ketones by α-Alkylation
28:01
Retrosynthesis of a Ketone
30:10
Acetoacetate Ester Synthesis of Ketones
31:05
Acetoacetate Ester Synthesis of Ketones: Step 1
31:06
Acetoacetate Ester Synthesis of Ketones: Step 2
32:13
Acetoacetate Ester Synthesis of Ketones: Step 3
32:50
Example: Synthesis of a Ketone
34:11
Example: Synthesis of a Ketone
34:12
Synthesis of Carboxylic Acids
37:15
Synthesis of Carboxylic Acids
37:16
Example: Synthesis of a Carboxylic Acid
37:59
Example: Synthesis of a Carboxylic Acid (Option 1)
38:00
Example: Synthesis of a Carboxylic Acid (Option 2)
40:51
Malonic Ester Synthesis of Carboxylic Acid
42:34
Malonic Ester Synthesis of Carboxylic Acid: Step 1
42:35
Malonic Ester Synthesis of Carboxylic Acid: Step 2
43:36
Malonic Ester Synthesis of Carboxylic Acid: Step 3
44:01
Example: Synthesis of a Carboxylic Acid
44:53
Example: Synthesis of a Carboxylic Acid
44:54
Synthesis of Carboxylic Acid Derivatives
48:05
Synthesis of Carboxylic Acid Derivatives
48:06
Alternate Ester Synthesis
48:58
Using Fischer Esterification
48:59
Using SN2 Reaction
50:18
Using Diazomethane
50:56
Using 1) LDA, 2) R'-X
52:15
Practice: Synthesis of an Alkyl Chloride
53:11
Practice: Synthesis of an Alkyl Chloride
53:12
Patterns of Functional Groups in Target Molecules
59:53
Recall: Aldol Reaction
59:54
β-hydroxy Ketone Target Molecule
01:12
α,β-unsaturated Ketone Target Molecule
02:20
Patterns of Functional Groups in Target Molecules
03:15
Recall: Michael Reaction
03:16
Retrosynthesis: 1,5-dicarbonyl Target Molecule
04:07
Patterns of Functional Groups in Target Molecules
06:38
Recall: Claisen Condensation
06:39
Retrosynthesis: β-ketoester Target Molecule
07:30
2-Group Target Molecule Summary
09:03
2-Group Target Molecule Summary
09:04
Example: Synthesis of Epoxy Ketone
11:19
Synthesize the Following Target Molecule from Cyclohexanone: Part 1 - Retrosynthesis
11:20
Synthesize the Following Target Molecule from Cyclohexanone: Part 2 - Synthesis
14:10
Example: Synthesis of a Diketone
16:57
Synthesis of a Diketone: Step 1 - Retrosynthesis
16:58
Synthesis of a Diketone: Step 2 - Synthesis
18:51
XII. Organic Synthesis & Organic Analysis
Organic Analysis: Classical & Modern Methods

46m 46s

Intro
0:00
Organic Analysis: Classical Methods
0:17
Classical Methods for Identifying Chemicals
0:18
Organic Analysis: Classical Methods
2:21
When is Structure Identification Needed?
2:22
Organic Analysis: Classical Methods
6:17
Classical Methods of Structure Identification: Physical Appearance
6:18
Classical Methods of Structure Identification: Physical Constants
6:42
Organic Analysis: Classical Methods
7:37
Classical Methods of Structure Identification: Solubility Tests - Water
7:38
Organic Analysis: Classical Methods
10:51
Classical Methods of Structure Identification: Solubility Tests - 5% aq. HCl Basic FG (Amines)
10:52
Organic Analysis: Classical Methods
11:50
Classical Methods of Structure Identification: Solubility Tests - 5% aq. NaOH Acidic FG (Carboxylic Acids, Phenols)
11:51
Organic Analysis: Classical Methods
13:28
Classical Methods of Structure Identification: Solubility Tests - 5% aq. NaHCO3 Strongly Acidic FG (Carboxylic Acids)
13:29
Organic Analysis: Classical Methods
15:35
Classical Methods of Structure Identification: Solubility Tests - Insoluble in All of the Above
15:36
Organic Analysis: Classical Methods
16:49
Classical Methods of Structure Identification: Idoform Test for Methyl Ketones
16:50
Organic Analysis: Classical Methods
22:02
Classical Methods of Structure Identification: Tollens' Test or Fehling's Solution for Aldehydes
22:03
Organic Analysis: Classical Methods
25:01
Useful Application of Classical Methods: Glucose Oxidase on Glucose Test Strips
25:02
Organic Analysis: Classical Methods
26:26
Classical Methods of Structure Identification: Starch-iodide Test
26:27
Organic Analysis: Classical Methods
28:22
Classical Methods of Structure Identification: Lucas Reagent to Determine Primary/Secondary/Tertiary Alcohol
28:23
Organic Analysis: Classical Methods
31:35
Classical Methods of Structure Identification: Silver Nitrate Test for Alkyl Halides
31:36
Organic Analysis: Classical Methods
33:23
Preparation of Derivatives
33:24
Organic Analysis: Modern Methods
36:55
Modern Methods of Chemical Characterization
36:56
Organic Analysis: Modern Methods
40:36
Checklist for Manuscripts Submitted to the ACS Journal Organic Letters
40:37
Organic Analysis: Modern Methods
42:39
Checklist for Manuscripts Submitted to the ACS Journal Organic Letters
42:40
Analysis of Stereochemistry

1h 2m 52s

Intro
0:00
Chirality & Optical Activity
0:32
Levorotatory & Dextrorotatory
0:33
Example: Optically Active?
2:22
Example: Optically Active?
2:23
Measurement of Specific Rotation, [α]
5:09
Measurement of Specific Rotation, [α]
5:10
Example: Calculation of Specific Rotation
8:56
Example: Calculation of Specific Rotation
8:57
Variability of Specific Rotation, [α]
12:52
Variability of Specific Rotation, [α]
12:53
Other Measures of Optical Activity: ORD and CD
15:04
Optical Rotary Dispersion (ORD)
15:05
Circular Dischroism (CD)
18:32
Circular Dischroism (CD)
18:33
Mixtures of Enantiomers
20:16
Racemic Mixtures
20:17
Unequal Mixtures of Enantiomers
21:36
100% ee
22:48
0% ee
23:34
Example: Definition of ee?
24:00
Example: Definition of ee?
24:01
Analysis of Optical Purity: [α]
27:47
[α] Measurement Can Be Used for Known Compounds
27:48
Analysis of Optical Purity: [α]
34:30
NMR Methods Using a Chiral Derivatizing Agent (CDA): Mosher's Reagent
34:31
Analysis of Optical Purity: [α]
40:01
NMR Methods Using a Chiral Derivatizing Agent (CDA): CDA Salt Formation
40:02
Analysis of Optical Purity: Chromatography
42:46
Chiral Chromatography
42:47
Stereochemistry Analysis by NMR: J Values (Coupling Constant)
51:28
NMR Methods for Structure Determination
51:29
Stereochemistry Analysis by NRM: NOE
57:00
NOE - Nuclear Overhauser Effect ( 2D Versions: NOESY or ROESY)
57:01
XIII. Spectroscopy
Infrared Spectroscopy, Part I

1h 4m

Intro
0:00
Infrared (IR) Spectroscopy
0:09
Introduction to Infrared (IR) Spectroscopy
0:10
Intensity of Absorption Is Proportional to Change in Dipole
3:08
IR Spectrum of an Alkane
6:08
Pentane
6:09
IR Spectrum of an Alkene
13:12
1-Pentene
13:13
IR Spectrum of an Alkyne
15:49
1-Pentyne
15:50
IR Spectrum of an Aromatic Compound
18:02
Methylbenzene
18:24
IR of Substituted Aromatic Compounds
24:04
IR of Substituted Aromatic Compounds
24:05
IR Spectrum of 1,2-Disubstituted Aromatic
25:30
1,2-dimethylbenzene
25:31
IR Spectrum of 1,3-Disubstituted Aromatic
27:15
1,3-dimethylbenzene
27:16
IR Spectrum of 1,4-Disubstituted Aromatic
28:41
1,4-dimethylbenzene
28:42
IR Spectrum of an Alcohol
29:34
1-pentanol
29:35
IR Spectrum of an Amine
32:39
1-butanamine
32:40
IR Spectrum of a 2° Amine
34:50
Diethylamine
34:51
IR Spectrum of a 3° Amine
35:47
Triethylamine
35:48
IR Spectrum of a Ketone
36:41
2-butanone
36:42
IR Spectrum of an Aldehyde
40:10
Pentanal
40:11
IR Spectrum of an Ester
42:38
Butyl Propanoate
42:39
IR Spectrum of a Carboxylic Acid
44:26
Butanoic Acid
44:27
Sample IR Correlation Chart
47:36
Sample IR Correlation Chart: Wavenumber and Functional Group
47:37
Predicting IR Spectra: Sample Structures
52:06
Example 1
52:07
Example 2
53:29
Example 3
54:40
Example 4
57:08
Example 5
58:31
Example 6
59:07
Example 7
00:52
Example 8
02:20
Infrared Spectroscopy, Part II

48m 34s

Intro
0:00
Interpretation of IR Spectra: a Basic Approach
0:05
Interpretation of IR Spectra: a Basic Approach
0:06
Other Peaks to Look for
3:39
Examples
5:17
Example 1
5:18
Example 2
9:09
Example 3
11:52
Example 4
14:03
Example 5
16:31
Example 6
19:31
Example 7
22:32
Example 8
24:39
IR Problems Part 1
28:11
IR Problem 1
28:12
IR Problem 2
31:14
IR Problem 3
32:59
IR Problem 4
34:23
IR Problem 5
35:49
IR Problem 6
38:20
IR Problems Part 2
42:36
IR Problem 7
42:37
IR Problem 8
44:02
IR Problem 9
45:07
IR Problems10
46:10
Nuclear Magnetic Resonance (NMR) Spectroscopy, Part I

1h 32m 14s

Intro
0:00
Purpose of NMR
0:14
Purpose of NMR
0:15
How NMR Works
2:17
How NMR Works
2:18
Information Obtained From a ¹H NMR Spectrum
5:51
No. of Signals, Integration, Chemical Shifts, and Splitting Patterns
5:52
Number of Signals in NMR (Chemical Equivalence)
7:52
Example 1: How Many Signals in ¹H NMR?
7:53
Example 2: How Many Signals in ¹H NMR?
9:36
Example 3: How Many Signals in ¹H NMR?
12:15
Example 4: How Many Signals in ¹H NMR?
13:47
Example 5: How Many Signals in ¹H NMR?
16:12
Size of Signals in NMR (Peak Area or Integration)
21:23
Size of Signals in NMR (Peak Area or Integration)
21:24
Using Integral Trails
25:15
Example 1: C₈H₁₈O
25:16
Example 2: C₃H₈O
27:17
Example 3: C₇H₈
28:21
Location of NMR Signal (Chemical Shift)
29:05
Location of NMR Signal (Chemical Shift)
29:06
¹H NMR Chemical Shifts
33:20
¹H NMR Chemical Shifts
33:21
¹H NMR Chemical Shifts (Protons on Carbon)
37:03
¹H NMR Chemical Shifts (Protons on Carbon)
37:04
Chemical Shifts of H's on N or O
39:01
Chemical Shifts of H's on N or O
39:02
Estimating Chemical Shifts
41:13
Example 1: Estimating Chemical Shifts
41:14
Example 2: Estimating Chemical Shifts
43:22
Functional Group Effects are Additive
45:28
Calculating Chemical Shifts
47:38
Methylene Calculation
47:39
Methine Calculation
48:20
Protons on sp³ Carbons: Chemical Shift Calculation Table
48:50
Example: Estimate the Chemical Shift of the Selected H
50:29
Effects of Resonance on Chemical Shifts
53:11
Example 1: Effects of Resonance on Chemical Shifts
53:12
Example 2: Effects of Resonance on Chemical Shifts
55:09
Example 3: Effects of Resonance on Chemical Shifts
57:08
Shape of NMR Signal (Splitting Patterns)
59:17
Shape of NMR Signal (Splitting Patterns)
59:18
Understanding Splitting Patterns: The 'n+1 Rule'
01:24
Understanding Splitting Patterns: The 'n+1 Rule'
01:25
Explanation of n+1 Rule
02:42
Explanation of n+1 Rule: One Neighbor
02:43
Explanation of n+1 Rule: Two Neighbors
06:23
Summary of Splitting Patterns
06:24
Summary of Splitting Patterns
10:45
Predicting ¹H NMR Spectra
10:46
Example 1: Predicting ¹H NMR Spectra
13:30
Example 2: Predicting ¹H NMR Spectra
19:07
Example 3: Predicting ¹H NMR Spectra
23:50
Example 4: Predicting ¹H NMR Spectra
29:27
Nuclear Magnetic Resonance (NMR) Spectroscopy, Part II

2h 3m 48s

Intro
0:00
¹H NMR Problem-Solving Strategies
0:18
Step 1: Analyze IR Spectrum (If Provided)
0:19
Step 2: Analyze Molecular Formula (If Provided)
2:06
Step 3: Draw Pieces of Molecule
3:49
Step 4: Confirm Pieces
6:30
Step 5: Put the Pieces Together!
7:23
Step 6: Check Your Answer!
8:21
Examples
9:17
Example 1: Determine the Structure of a C₉H₁₀O₂ Compound with the Following ¹H NMR Data
9:18
Example 2: Determine the Structure of a C₉H₁₀O₂ Compound with the Following ¹H NMR Data
17:27
¹H NMR Practice
20:57
¹H NMR Practice 1: C₁₀H₁₄
20:58
¹H NMR Practice 2: C₄H₈O₂
29:50
¹H NMR Practice 3: C₆H₁₂O₃
39:19
¹H NMR Practice 4: C₈H₁₈
50:19
More About Coupling Constants (J Values)
57:11
Vicinal (3-bond) and Geminal (2-bond)
57:12
Cyclohexane (ax-ax) and Cyclohexane (ax-eq) or (eq-eq)
59:50
Geminal (Alkene), Cis (Alkene), and Trans (Alkene)
02:40
Allylic (4-bond) and W-coupling (4-bond) (Rigid Structures Only)
04:05
¹H NMR Advanced Splitting Patterns
05:39
Example 1: ¹H NMR Advanced Splitting Patterns
05:40
Example 2: ¹H NMR Advanced Splitting Patterns
10:01
Example 3: ¹H NMR Advanced Splitting Patterns
13:45
¹H NMR Practice
22:53
¹H NMR Practice 5: C₁₁H₁₇N
22:54
¹H NMR Practice 6: C₉H₁₀O
34:04
¹³C NMR Spectroscopy
44:49
¹³C NMR Spectroscopy
44:50
¹³C NMR Chemical Shifts
47:24
¹³C NMR Chemical Shifts Part 1
47:25
¹³C NMR Chemical Shifts Part 2
48:59
¹³C NMR Practice
50:16
¹³C NMR Practice 1
50:17
¹³C NMR Practice 2
58:30
C-13 DEPT NMR Experiments

23m 10s

Intro
0:00
C-13 DEPT NMR Spectoscopy
0:13
Overview
0:14
C-13 DEPT NMR Spectoscopy, Cont.
3:31
Match C-13 Peaks to Carbons on Structure
3:32
C-13 DEPT NMR Spectoscopy, Cont.
8:46
Predict the DEPT-90 and DEPT-135 Spectra for the Given Compound
8:47
C-13 DEPT NMR Spectoscopy, Cont.
12:30
Predict the DEPT-90 and DEPT-135 Spectra for the Given Compound
12:31
C-13 DEPT NMR Spectoscopy, Cont.
17:19
Determine the Structure of an Unknown Compound using IR Spectrum and C-13 DEPT NMR
17:20
Two-Dimensional NMR Techniques: COSY

33m 39s

Intro
0:00
Two-Dimensional NMR Techniques: COSY
0:14
How Do We Determine Which Protons are Related in the NMR?
0:15
Two-Dimensional NMR Techniques: COSY
1:48
COSY Spectra
1:49
Two-Dimensional NMR Techniques: COSY
7:00
COSY Correlation
7:01
Two-Dimensional NMR Techniques: COSY
8:55
Complete the COSY NMR Spectrum for the Given Compoun
8:56
NMR Practice Problem
15:40
Provide a Structure for the Unknown Compound with the H NMR and COSY Spectra Shown
15:41
Two-Dimensional NMR Techniques: HETCOR & HMBC

15m 5s

Intro
0:00
HETCOR
0:15
Heteronuclear Correlation Spectroscopy
0:16
HETCOR
2:04
HETCOR Example
2:05
HMBC
11:07
Heteronuclear Multiple Bond Correlation
11:08
HMBC
13:14
HMB Example
13:15
Mass Spectrometry

1h 28m 35s

Intro
0:00
Introduction to Mass Spectrometry
0:37
Uses of Mass Spectrometry: Molecular Mass
0:38
Uses of Mass Spectrometry: Molecular Formula
1:04
Uses of Mass Spectrometry: Structural Information
1:21
Uses of Mass Spectrometry: In Conjunction with Gas Chromatography
2:03
Obtaining a Mass Spectrum
2:59
Obtaining a Mass Spectrum
3:00
The Components of a Mass Spectrum
6:44
The Components of a Mass Spectrum
6:45
What is the Mass of a Single Molecule
12:13
Example: CH₄
12:14
Example: ¹³CH₄
12:51
What Ratio is Expected for the Molecular Ion Peaks of C₂H₆?
14:20
Other Isotopes of High Abundance
16:30
Example: Cl Atoms
16:31
Example: Br Atoms
18:33
Mass Spectrometry of Chloroethane
19:22
Mass Spectrometry of Bromobutane
21:23
Isotopic Abundance can be Calculated
22:48
What Ratios are Expected for the Molecular Ion Peaks of CH₂Br₂?
22:49
Determining Molecular Formula from High-resolution Mass Spectrometry
26:53
Exact Masses of Various Elements
26:54
Fragmentation of various Functional Groups
28:42
What is More Stable, a Carbocation C⁺ or a Radical R?
28:43
Fragmentation is More Likely If It Gives Relatively Stable Carbocations and Radicals
31:37
Mass Spectra of Alkanes
33:15
Example: Hexane
33:16
Fragmentation Method 1
34:19
Fragmentation Method 2
35:46
Fragmentation Method 3
36:15
Mass of Common Fragments
37:07
Mass of Common Fragments
37:08
Mass Spectra of Alkanes
39:28
Mass Spectra of Alkanes
39:29
What are the Peaks at m/z 15 and 71 So Small?
41:01
Branched Alkanes
43:12
Explain Why the Base Peak of 2-methylhexane is at m/z 43 (M-57)
43:13
Mass Spectra of Alkenes
45:42
Mass Spectra of Alkenes: Remove 1 e⁻
45:43
Mass Spectra of Alkenes: Fragment
46:14
High-Energy Pi Electron is Most Likely Removed
47:59
Mass Spectra of Aromatic Compounds
49:01
Mass Spectra of Aromatic Compounds
49:02
Mass Spectra of Alcohols
51:32
Mass Spectra of Alcohols
51:33
Mass Spectra of Ethers
54:53
Mass Spectra of Ethers
54:54
Mass Spectra of Amines
56:49
Mass Spectra of Amines
56:50
Mass Spectra of Aldehydes & Ketones
59:23
Mass Spectra of Aldehydes & Ketones
59:24
McLafferty Rearrangement
01:29
McLafferty Rearrangement
01:30
Mass Spectra of Esters
04:15
Mass Spectra of Esters
01:16
Mass Spectrometry Discussion I
05:01
For the Given Molecule (M=58), Do You Expect the More Abundant Peak to Be m/z 15 or m/z 43?
05:02
Mass Spectrometry Discussion II
08:13
For the Given Molecule (M=74), Do You Expect the More Abundant Peak to Be m/z 31, m/z 45, or m/z 59?
08:14
Mass Spectrometry Discussion III
11:42
Explain Why the Mass Spectra of Methyl Ketones Typically have a Peak at m/z 43
11:43
Mass Spectrometry Discussion IV
14:46
In the Mass Spectrum of the Given Molecule (M=88), Account for the Peaks at m/z 45 and m/z 57
14:47
Mass Spectrometry Discussion V
18:25
How Could You Use Mass Spectrometry to Distinguish Between the Following Two Compounds (M=73)?
18:26
Mass Spectrometry Discussion VI
22:45
What Would be the m/z Ratio for the Fragment for the Fragment Resulting from a McLafferty Rearrangement for the Following Molecule (M=114)?
22:46
XIV. Organic Chemistry Lab
Completing the Reagent Table for Prelab

21m 9s

Intro
0:00
Sample Reagent Table
0:11
Reagent Table Overview
0:12
Calculate Moles of 2-bromoaniline
6:44
Calculate Molar Amounts of Each Reagent
9:20
Calculate Mole of NaNO₂
9:21
Calculate Moles of KI
10:33
Identify the Limiting Reagent
11:17
Which Reagent is the Limiting Reagent?
11:18
Calculate Molar Equivalents
13:37
Molar Equivalents
13:38
Calculate Theoretical Yield
16:40
Theoretical Yield
16:41
Calculate Actual Yield (%Yield)
18:30
Actual Yield (%Yield)
18:31
Introduction to Melting Points

16m 10s

Intro
0:00
Definition of a Melting Point (mp)
0:04
Definition of a Melting Point (mp)
0:05
Solid Samples Melt Gradually
1:49
Recording Range of Melting Temperature
2:04
Melting Point Theory
3:14
Melting Point Theory
3:15
Effects of Impurities on a Melting Point
3:57
Effects of Impurities on a Melting Point
3:58
Special Exception: Eutectic Mixtures
5:09
Freezing Point Depression by Solutes
5:39
Melting Point Uses
6:19
Solid Compound
6:20
Determine Purity of a Sample
6:42
Identify an Unknown Solid
7:06
Recording a Melting Point
9:03
Pack 1-3 mm of Dry Powder in MP Tube
9:04
Slowly Heat Sample
9:55
Record Temperature at First Sign of Melting
10:33
Record Temperature When Last Crystal Disappears
11:26
Discard MP Tube in Glass Waste
11:32
Determine Approximate MP
11:42
Tips, Tricks and Warnings
12:28
Use Small, Tightly Packed Sample
12:29
Be Sure MP Apparatus is Cool
12:45
Never Reuse a MP Tube
13:16
Sample May Decompose
13:30
If Pure Melting Point (MP) Doesn't Match Literature
14:20
Melting Point Lab

8m 17s

Intro
0:00
Melting Point Tubes
0:40
Melting Point Apparatus
3:42
Recording a melting Point
5:50
Introduction to Recrystallization

22m

Intro
0:00
Crystallization to Purify a Solid
0:10
Crude Solid
0:11
Hot Solution
0:20
Crystals
1:09
Supernatant Liquid
1:20
Theory of Crystallization
2:34
Theory of Crystallization
2:35
Analysis and Obtaining a Second Crop
3:40
Crystals → Melting Point, TLC
3:41
Supernatant Liquid → Crude Solid → Pure Solid
4:18
Crystallize Again → Pure Solid (2nd Crop)
4:32
Choosing a Solvent
5:19
1. Product is Very Soluble at High Temperatures
5:20
2. Product has Low Solubility at Low Temperatures
6:00
3. Impurities are Soluble at All Temperatures
6:16
Check Handbooks for Suitable Solvents
7:33
Why Isn't This Dissolving?!
8:46
If Solid Remains When Solution is Hot
8:47
Still Not Dissolved in Hot Solvent?
10:18
Where Are My Crystals?!
12:23
If No Crystals Form When Solution is Cooled
12:24
Still No Crystals?
14:59
Tips, Tricks and Warnings
16:26
Always Use a Boiling Chip or Stick!
16:27
Use Charcoal to Remove Colored Impurities
16:52
Solvent Pairs May Be Used
18:23
Product May 'Oil Out'
20:11
Recrystallization Lab

19m 7s

Intro
0:00
Step 1: Dissolving the Solute in the Solvent
0:12
Hot Filtration
6:33
Step 2: Cooling the Solution
8:01
Step 3: Filtering the Crystals
12:08
Step 4: Removing & Drying the Crystals
16:10
Introduction to Distillation

25m 54s

Intro
0:00
Distillation: Purify a Liquid
0:04
Simple Distillation
0:05
Fractional Distillation
0:55
Theory of Distillation
1:04
Theory of Distillation
1:05
Vapor Pressure and Volatility
1:52
Vapor Pressure
1:53
Volatile Liquid
2:28
Less Volatile Liquid
3:09
Vapor Pressure vs. Boiling Point
4:03
Vapor Pressure vs. Boiling Point
4:04
Increasing Vapor Pressure
4:38
The Purpose of Boiling Chips
6:46
The Purpose of Boiling Chips
6:47
Homogeneous Mixtures of Liquids
9:24
Dalton's Law
9:25
Raoult's Law
10:27
Distilling a Mixture of Two Liquids
11:41
Distilling a Mixture of Two Liquids
11:42
Simple Distillation: Changing Vapor Composition
12:06
Vapor & Liquid
12:07
Simple Distillation: Changing Vapor Composition
14:47
Azeotrope
18:41
Fractional Distillation: Constant Vapor Composition
19:42
Fractional Distillation: Constant Vapor Composition
19:43
Distillation Lab

24m 13s

Intro
0:00
Glassware Overview
0:04
Heating a Sample
3:09
Bunsen Burner
3:10
Heating Mantle 1
4:45
Heating Mantle 2
6:18
Hot Plate
7:10
Simple Distillation Lab
8:37
Fractional Distillation Lab
17:13
Removing the Distillation Set-Up
22:41
Introduction to TLC (Thin-Layer Chromatography)

28m 51s

Intro
0:00
Chromatography
0:06
Purification & Analysis
0:07
Types of Chromatography: Thin-layer, Column, Gas, & High Performance Liquid
0:24
Theory of Chromatography
0:44
Theory of Chromatography
0:45
Performing a Thin-layer Chromatography (TLC) Analysis
2:30
Overview: Thin-layer Chromatography (TLC) Analysis
2:31
Step 1: 'Spot' the TLC Plate
4:11
Step 2: Prepare the Developing Chamber
5:54
Step 3: Develop the TLC Plate
7:30
Step 4: Visualize the Spots
9:02
Step 5: Calculate the Rf for Each Spot
12:00
Compound Polarity: Effect on Rf
16:50
Compound Polarity: Effect on Rf
16:51
Solvent Polarity: Effect on Rf
18:47
Solvent Polarity: Effect on Rf
18:48
Example: EtOAc & Hexane
19:35
Other Types of Chromatography
22:27
Thin-layer Chromatography (TLC)
22:28
Column Chromatography
22:56
High Performance Liquid (HPLC)
23:59
Gas Chromatography (GC)
24:38
Preparative 'prep' Scale Possible
28:05
TLC Analysis Lab

20m 50s

Intro
0:00
Step 1: 'Spot' the TLC Plate
0:06
Step 2: Prepare the Developing Chamber
4:06
Step 3: Develop the TLC Plate
6:26
Step 4: Visualize the Spots
7:45
Step 5: Calculate the Rf for Each Spot
11:48
How to Make Spotters
12:58
TLC Plate
16:04
Flash Column Chromatography
17:11
Introduction to Extractions

34m 25s

Intro
0:00
Extraction Purify, Separate Mixtures
0:07
Adding a Second Solvent
0:28
Mixing Two Layers
0:38
Layers Settle
0:54
Separate Layers
1:05
Extraction Uses
1:20
To Separate Based on Difference in Solubility/Polarity
1:21
To Separate Based on Differences in Reactivity
2:11
Separate & Isolate
2:20
Theory of Extraction
3:03
Aqueous & Organic Phases
3:04
Solubility: 'Like Dissolves Like'
3:25
Separation of Layers
4:06
Partitioning
4:14
Distribution Coefficient, K
5:03
Solutes Partition Between Phases
5:04
Distribution Coefficient, K at Equilibrium
6:27
Acid-Base Extractions
8:09
Organic Layer
8:10
Adding Aqueous HCl & Mixing Two Layers
8:46
Neutralize (Adding Aqueous NaOH)
10:05
Adding Organic Solvent Mix Two Layers 'Back Extract'
10:24
Final Results
10:43
Planning an Acid-Base Extraction, Part 1
11:01
Solute Type: Neutral
11:02
Aqueous Solution: Water
13:40
Solute Type: Basic
14:43
Solute Type: Weakly Acidic
15:23
Solute Type: Acidic
16:12
Planning an Acid-Base Extraction, Part 2
17:34
Planning an Acid-Base Extraction
17:35
Performing an Extraction
19:34
Pour Solution into Sep Funnel
19:35
Add Second Liquid
20:07
Add Stopper, Cover with Hand, Remove from Ring
20:48
Tip Upside Down, Open Stopcock to Vent Pressure
21:00
Shake to Mix Two Layers
21:30
Remove Stopper & Drain Bottom Layer
21:40
Reaction Work-up: Purify, Isolate Product
22:03
Typical Reaction is Run in Organic Solvent
22:04
Starting a Reaction Work-up
22:33
Extracting the Product with Organic Solvent
23:17
Combined Extracts are Washed
23:40
Organic Layer is 'Dried'
24:23
Finding the Product
26:38
Which Layer is Which?
26:39
Where is My Product?
28:00
Tips, Tricks and Warnings
29:29
Leaking Sep Funnel
29:30
Caution When Mixing Layers & Using Ether
30:17
If an Emulsion Forms
31:51
Extraction Lab

14m 49s

Intro
0:00
Step 1: Preparing the Separatory Funnel
0:03
Step 2: Adding Sample
1:18
Step 3: Mixing the Two Layers
2:59
Step 4: Draining the Bottom Layers
4:59
Step 5: Performing a Second Extraction
5:50
Step 6: Drying the Organic Layer
7:21
Step 7: Gravity Filtration
9:35
Possible Extraction Challenges
12:55
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Lecture Comments (17)

1 answer

Last reply by: Professor Starkey
Wed Aug 2, 2017 12:52 AM

Post by Andrew Mullins on July 31, 2017

Hi Dr. Starkey,
for the final section of acidity of carboxylic acids, you mentioned that the strongest acid would be the last benzoic acid. However, you said that the fluorine was the farthest away from the negative oxygen, yet the fluorine is bonded to the carbon right beside it. This doesn't make sense to me. Is there supposed to be a 3D version in mind that causes this distance or is there another reason?

-Andrew

1 answer

Last reply by: Professor Starkey
Tue Apr 21, 2015 1:01 AM

Post by sarit nahari on April 20, 2015

Hello, I am a medical student at Tel Aviv University. Because  your's  wonderful explanations, I'm starting to love organic chemistry.
Thank you very much.
Bono

1 answer

Last reply by: Professor Starkey
Wed Mar 11, 2015 1:03 AM

Post by Nicole Aquino on March 10, 2015

Thank you for the lectures. It helped me a lot. I'm a Medical laboratory student and i'm very glad to discover this page. :)

1 answer

Last reply by: Professor Starkey
Sun Dec 8, 2013 6:56 PM

Post by Annie An on December 8, 2013

What if i want to compare the water solubility of similar sized alcohols, aldehydes and carboxylic acids?
What kinds of things that i supposed to consider to compare them?

1 answer

Last reply by: Professor Starkey
Fri Jul 19, 2013 8:35 AM

Post by mateusz marciniak on July 18, 2013

hi professor i would like to thank you for your lecture series, it has helped me get through my summer orgo I course. i just wish you did some harder examples in each lecture series, some were difficult but others i thought a were a little too easy, nonetheless excellent lecture series

1 answer

Last reply by: Professor Starkey
Sun Apr 7, 2013 12:08 PM

Post by Edi William Yapi on April 6, 2013

Great Lecture !

1 answer

Last reply by: Professor Starkey
Sun Feb 17, 2013 5:23 PM

Post by natasha plantak on February 15, 2013

Your lectures are extremely helpful. Thank you so much!
~Natasha

1 answer

Last reply by: Professor Starkey
Thu Feb 2, 2012 11:01 AM

Post by Jason Jarduck on January 29, 2012

Hi Dr. Starkey

I really liked your lecture. I'm going to be looking forward to organic chemistry III as well. Very good information. Very clear.

Thank You

Jason

0 answers

Post by Billy Jay on March 28, 2011

Hmmm. Something's different...

Carboxylic Acids

Rank the following compounds in order of increasing acidity:
  • CH3CH2-COOH is the least acidic because it has a pKa of 4.9
  • CF3-COOH is the most acidic because of the three electron-withdrawing F's. It has a pKa of 0.2
  • ICH2-COOH is stronger than CH3CH2-COOH but only has one electron-withdrawing group so it ranks lower than CF3-COOH
Identify the starting compound in this reaction:
  • This is an oxidation of alkenes/alkynes reaction (Ozonolysis)
Devise a synthesis for this reaction:
  • Step 1:
  • Step 2:
  • Step 3:
Rank the following compounds in order of increasing acidity:
  • Cl is more electronegative than Br
Draw the mechanism leading to the product for this reaction:
  • Step 1:
  • Step 2:
  • Step 3:
  • Step 4:
  • Step 5:
  • Step 6:
Draw the product for this reaction:

*These practice questions are only helpful when you work on them offline on a piece of paper and then use the solution steps function to check your answer.

Answer

Carboxylic Acids

Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.

  1. Intro
    • Review Reactions of Ketone/Aldehyde
    • Review Reactions of Ketone/Aldehyde
    • Carboxylic Acids and Their Derivatives
    • Ketone vs. Ester Reactivity
    • Carboxylic Acids and Their Derivatives
    • General Reactions of Acarboxylic Acid Derivatives
    • Physical Properties of Carboxylic Acids
    • Aciditiy of Carboxylic Acids, RCO₂H
    • Aciditiy of Carboxylic Acids, RCO₂H
    • Aciditiy of Carboxylic Acids, RCO₂H
    • Aciditiy of Carboxylic Acids, RCO₂H
    • Preparation of Carboxylic Acids, RCO₂H
    • Preparation of Carboxylic Acids, RCO₂H
    • Preparation of Carboxylic Acids, RCO₂H
    • Preparation of Carboxylic Acids, RCO₂H
    • Preparation of Carboxylic Acids, RCO₂H
    • Hydrolysis Mechanism
    • Hydrolysis Mechanism
    • Hydrolysis Mechanism
    • Applications of Carboxylic Acid Derivatives:
    • Ester Hydrolysis
    • Ester Hydrolysis Requires Acide or Base
    • Nitrile Hydrolysis
    • Nitrile Hydrolysis Mechanism
    • Use of Nitriles in Synthesis
    • Intro 0:00
    • Review Reactions of Ketone/Aldehyde 0:06
      • Carbonyl Reactivity
      • Nu: = Hydride (Reduction)
      • Nu: = Grignard
    • Review Reactions of Ketone/Aldehyde 2:53
      • Nu: = Alcohol
      • Nu: = Amine
    • Carboxylic Acids and Their Derivatives 4:37
      • Carboxylic Acids and Their Derivatives
    • Ketone vs. Ester Reactivity 6:33
      • Ketone Reactivity
      • Ester Reactivity
    • Carboxylic Acids and Their Derivatives 7:30
      • Acid Halide, Anhydride, Ester, Amide, and Nitrile
    • General Reactions of Acarboxylic Acid Derivatives 9:22
      • General Reactions of Acarboxylic Acid Derivatives
    • Physical Properties of Carboxylic Acids 12:16
      • Acetic Acid
      • Carboxylic Acids
    • Aciditiy of Carboxylic Acids, RCO₂H 17:45
      • Alcohol
      • Carboxylic Acid
    • Aciditiy of Carboxylic Acids, RCO₂H 21:31
      • Aciditiy of Carboxylic Acids, RCO₂H
    • Aciditiy of Carboxylic Acids, RCO₂H 24:48
      • Example: Which is the Stronger Acid?
    • Aciditiy of Carboxylic Acids, RCO₂H 30:06
      • Inductive Effects Decrease with Distance
    • Preparation of Carboxylic Acids, RCO₂H 31:55
      • A) By Oxidation
    • Preparation of Carboxylic Acids, RCO₂H 34:37
      • Oxidation of Alkenes/Alkynes - Ozonolysis
    • Preparation of Carboxylic Acids, RCO₂H 36:17
      • B) Preparation of RCO₂H from Organometallic Reagents
    • Preparation of Carboxylic Acids, RCO₂H 38:02
      • Example: Preparation of Carboxylic Acids
    • Preparation of Carboxylic Acids, RCO₂H 40:38
      • C) Preparation of RCO₂H by Hydrolysis of Carboxylic Acid Derivatives
    • Hydrolysis Mechanism 42:19
      • Hydrolysis Mechanism
      • Mechanism: Acyl Substitution (Addition/Elimination)
    • Hydrolysis Mechanism 47:27
      • Substitution Reaction
      • RO is Bad LG for SN1/SN2
      • RO is okay LG for Collapse of CTI
    • Hydrolysis Mechanism 50:07
      • Base-promoted Ester Hydrolysis (Saponification)
    • Applications of Carboxylic Acid Derivatives: 53:10
      • Saponification Reaction
    • Ester Hydrolysis 57:15
      • Acid-Catalyzed Mechanism
    • Ester Hydrolysis Requires Acide or Base 1:03:06
      • Ester Hydrolysis Requires Acide or Base
    • Nitrile Hydrolysis 1:05:22
      • Nitrile Hydrolysis
    • Nitrile Hydrolysis Mechanism 1:06:53
      • Nitrile Hydrolysis Mechanism
    • Use of Nitriles in Synthesis 1:12:39
      • Example: Nitirles in Synthesis

    Transcription: Carboxylic Acids

    Hello; welcome back to Educator.0000

    Today, we are going to be talking about carboxylic acids.0002

    Let's review what we know about carbonyls, that we have seen in aldehydes and ketones so far.0007

    A carbonyl is a C-O double bond, and what makes this functional group very special is that it has resonance, where we can draw a second Lewis structure.0013

    And any time we have resonance, that means that neither of these Lewis structures accurately reflects the actual structure of the carbonyl; it's some blend between these two.0024

    And so, each of them kind of describes the characteristics that the carbonyl has.0035

    So overall, every time that we see a carbonyl, we know that the carbonyl carbon has some significant partial positive character, and the carbonyl oxygen, some partial minus character.0040

    That means...the reaction as you have seen it so far is that the carbonyl carbon is electrophilic (in other words, nucleophiles add here), and the carbonyl oxygen, somewhat basic (in other words, we can protonate here).0052

    And, in fact, many, many reactions we have seen have started with...involved protonation of the carbonyl; and many, many reactions involve a nucleophilic attack on the carbonyl carbon.0071

    So, let's just review a few examples of these things we have seen already for aldehydes and ketones, because then we'll be able to compare that to how that differentiates (is different) from when we move into carboxylic acids and other function groups, known as carboxylic acid derivatives.0082

    For example, if we have a ketone, and we treat it with hydride (something like lithium aluminum hydride), that is a great nucleophile, we would expect that to add to the carbonyl, and then, after workup, we would protonate that O-, and we would get this alcohol product out.0097

    We describe that as a reduction reaction, because we have lost a C-O bond and traded it for a C-H bond and gone from a ketone to an alcohol.0119

    OK, a Grignard reaction, instead of an H-, gives us a C-; so this phenylmagnesium bromide would give us a source of phenol -; we could put that in quotes, just like we did we did for hydride (sorry, I didn't do that).0128

    We should put that in quotes, because this hydride is always coordinated with the aluminum; this carbon group is always coordinated with the magnesium; but it reacts just like that kind of nucleophile, and again, would attack the carbonyl.0142

    And then, after an aqueous workup, we would end up with an alcohol product.0154

    But, in this case, we would have a new carbon-carbon bond that we have also formed at the same time.0159

    This is just a few examples of nucleophiles that can add to carbonyls of aldehydes and ketones.0168

    Now, if we have heteroatom nucleophiles, like oxygen or nitrogen, our products look a little different; if our nucleophile is an alcohol, you can imagine that the same pattern we had for the hydride of the Grignard...our nucleophile, in this case, would a methoxy group; so we could add that in.0175

    But this alcohol product is no longer stable; having a single carbon with an OH and an OR group attached is not stable; so instead, this continues to react in the presence of acid catalyst, and we end up adding two equivalents of the alkoxy group, and we get out a product known as an acetal.0196

    Instead of having a carbonyl and two bonds to the same oxygen, we have two bonds to different oxygens; we have these methoxy groups.0220

    And, if we have a nitrogen nucleophile, again, you can imagine having this as an intermediate product--OK, but this, too, is unstable, having this alcohol, because this nitrogen with its lone pairs is going to come down and kick off that leaving group.0227

    At some point, we would probably protonate this, since we are acid-catalyzed, to make it a good leaving group.0246

    But ultimately, the products we get with an aldehyde or ketone and an amine are: we replace the C-O double bond with a C-N double bond, to give an imine product.0251

    So, these are all reactions that we have seen before for aldehydes and ketones, and we will see how those are going to be quite different from the next set of carbonyl-containing functional groups.0263

    We will see carboxylic acids and their derivatives.0275

    Now, a carboxylic acid is the functional group we have when we have a carbonyl; but instead of just carbons attached (like a ketone), or a carbon and a hydrogen (like an aldehyde), we have an OH group attached to that carbonyl.0278

    Now, that no longer is an alcohol functional group, or a ketone and aldehyde.0290

    This entire thing combines together to be described as a single functional group called a carboxylic acid.0294

    And if we want to think about its reactivity, we need to consider its resonance as well, and like every carbonyl, it has resonance that breaks the π bond and gives an O- and a C+.0303

    That is always true for any carbonyl; but by having this OH group, now, attached to the carbonyl carbon, we have additional resonance.0317

    That additional resonance comes about by this oxygen donating its lone pair of electrons and sharing it with that carbonyl (specifically, with that carbonyl carbon).0325

    We have a third resonance form that we can draw.0340

    How does that affect the reactivity of the carboxylic acid?0345

    Well, it turns out that this oxygen group, with its lone pair, donates electron density into the carbonyl.0349

    The OH group donates electron density, and that means that this carbonyl--the carboxylic acid--is more electron-rich than a ketone or an aldehyde.0358

    The effect of the oxygen is to add electron density into the carbonyl, making it more electron-rich.0369

    That makes the ketone or the aldehyde more partial positive and more electrophilic; so carboxylic acids and their derivatives (that we will see down the road), in general, are more electron-rich because of that electron donation.0375

    Certainly, if you have an oxygen group, you are like an OH.0389

    An example that we have seen of this before is when we used sodium borohydride as our hydride source, instead of lithium aluminum hydride.0395

    LAH is much more reactive; sodium borohydride is not as reactive--it's still reactive enough to react with a ketone and reduce it to the alcohol, but if we try to do that same reaction with an ester (the ester, remember, is less reactive, because this carbonyl is more electron-rich), we find that there is no reaction here.0403

    Sodium borohydride is...we say that NaBH4 is selective for aldehydes and ketones--it can reduce an aldehyde or ketone in the presence of an ester, because the ester is less reactive.0432

    Now, in this lesson, we are going to be talking about carboxylic acids, but in the next lesson, we are going to be talking about all of the related functional groups, called carboxylic acid derivatives.0452

    Let's introduce them at this point.0461

    If you have a halogen attached to a carbonyl, we call those acid halides; and usually, the x is chlorine; so it is usually the acid chloride that we are dealing with.0464

    If you have an oxygen surrounded by carbonyls on either side, that is known as an anhydride.0476

    If you have an OR group attached to carbonyl, it is called an ester.0482

    If you have a nitrogen attached to the carbonyl, we call that an amine.0487

    These all have the general structure of having attached the carbonyl--some kind of leaving group with a lone pair.0492

    So, this represents an atom with lone pairs; we describe it as a heteroatom, meaning "not carbon or hydrogen."0498

    If there is carbon or hydrogen, we describe it as an aldehyde or a ketone.0507

    But this has either a halide (we know halides, of course, are good leaving groups...and lone pairs); the leaving group on an anhydride is this oxygen with the carbonyl.0510

    So, for an anhydride, one of the carbonyls we consider as the electrophilic carbonyl; the rest of the group...the other carbonyl is part of the leaving group attached to that.0523

    The ester has an OR group attached as a leaving group; the amide has a nitrogen group attached as a leaving group; and then the nitrile doesn't really fit into the same pattern, but it, too, is a carboxylic acid derivative, because it has three bonds to a nitrogen, for example, instead of 2 to an oxygen and 1 to a nitrogen.0534

    It still has that same sort of pattern; we will look at nitriles a little later in the chapter.0555

    The reason that all of these functional groups are grouped together and considered as a unit is because they have the same general reactivity.0564

    OK, and a general reaction of a carbonyl with a leaving group attached is that, when it reacts with a nucleophile, the nucleophile attacks the carbonyl.0573

    And then, it might be tempting, now that you see something defined as a leaving group attached--it might be tempting to say, "Oh, well, that nucleophile just kicks out that leaving group, doesn't it?"0583

    Well, it can't; that would be an Sn2 mechanism: there are no Sn2's for carbonyls--carbonyls don't do that.0592

    But instead, the nucleophile attacks the carbonyl; and as always, it just breaks the π bond and puts those electrons up on the oxygen.0600

    OK, but when you look at the structure that is formed as a result, this structure is described as a charged tetrahedral intermediate (or a CTI for short).0610

    What defines a CTI is: you have a tetrahedral carbon (so in other words, an sp3 hybridized carbon with four groups attached)...so we have an sp3 hybridized carbon, and at least two groups have one or more lone pairs.0633

    So, for example, if we have an oxygen and an oxygen, or an oxygen and a chlorine, or a chlorine and a nitrogen--if we have at least two groups with lone pairs, we describe this as a CTI.0659

    What a CTI does is very special: it will collapse.0669

    When we see this pattern in an intermediate, we know that it is unstable, and it collapses.0674

    And what that means is that the leaving group will leave, but it leaves with the assistance of the other group with lone pairs.0679

    So, one group with a lone pair gets kicked out, and the other group with lone pairs helps push it out.0686

    And so, our leaving group leaves, and overall, what has happened is: we have had a substitution reaction take place (our leaving group has gone, and a nucleophile has taken its place).0695

    OK, but it is not a substitution mechanism we have seen before (for alkyl halides, for example); it is not an SN1 mechanism; it is not an SN2 mechanism; it is called an acyl substitution reaction.0706

    The mechanism can be described as addition-elimination.0718

    Our nucleophile adds into the carbonyl, and then the leaving group is eliminated by collapsing a CTI.0722

    We'll find it has both acid-catalyzed mechanisms and base-catalyzed mechanisms; we'll study both of those in today's lesson.0729

    Before we look at those reactions, though, let's think a little bit more about carboxylic acids as a functional group: what kind of behavior does it have?--what kind of physical properties?0739

    OK, so for example, let's take a look at this: this is acetic acid--this is a simple carboxylic acid: AcOH is how we could abbreviate this.0747

    The Ac group means we have a CH3 with a carbonyl; you will see that Ac group here in acetic acid, and it is common throughout all the carboxylic acid derivatives (acetyl chloride and acetic anhydride and acetic acid and so on).0756

    It is very good to be familiar with those common names.0775

    If you take a look at the physical properties, acetic acid is an interesting one because this is the acidic component that is in vinegar.0779

    So, the odor of acetic acid is very familiar to you; the bit that it has; the flavor that you have--that kind of burning sensation is this component in here.0790

    What does it have on here?--well, all carboxylic acids have the OH group; we know that the OH group is very polar, and any time you have an OH bond that is so polar that those groups can interact with other OH groups and can form hydrogen bonds, it's polar; it can form hydrogen bonds.0803

    It can form hydrogen bonds with itself; so, 2 molecules of acetic acid, in other words, can hydrogen bond to each other.0833

    That means it is going to have a high boiling point, and it can also form hydrogen bonds with water.0842

    That means it is going to have high water solubility.0852

    And, in fact, that is true: the boiling point for vinegar is 118 degrees Celsius, so even higher boiling than water--a very high boiling compound.0860

    It is miscible with water; so that means it is very highly water-soluble; and, in fact, vinegar is an aqueous solution, with acetic acid in there (a dilute aqueous solution).0873

    And so, you can't ever add enough acetic acid to water to have them separate out into two layers; it is always going to be a single solution, because it is miscible: it is soluble in all proportions.0886

    OK, and that is because it has this OH group; in addition, the second oxygen also has the carbonyl, which, of course, is also polar, and can do the same thing.0896

    It can hydrogen bond (form hydrogen bonds) with water; in other words, it can be a hydrogen bond acceptor.0905

    So, there are a lot of characteristics of carboxylic acid that make it very familiar with water and very much like water.0913

    OK, so when you see the RCO2H (that is how we abbreviate the carboxylic acid)--when you see that functional group, it is an extremely polar functional group.0922

    And remember, it has that resonance that we looked at on the first slide, too--on an earlier slide--that makes it even more polar with partial positive and partial negatives.0933

    OK, so it's an extremely polar functional group.0942

    Now, let's take a look at a different carboxylic acid; this one has, now, a longer carbon chain.0946

    It has two parts of the molecule: it has this carboxylic acid part, which is quite polar (can hydrogen bond and donate or can hydrogen bond and accept); so this part we would describe as being quite hydrophilic.0953

    But how about the rest of this carbon chain?0968

    Carbon-carbon bonds and carbon-hydrogen bonds are totally nonpolar.0971

    So that makes them hydrophobic, or you could even describe it as being greasy; this is something that would not like water at all.0977

    This actually has a pretty low solubility; this is insoluble in neutral water (this molecule).0994

    But if, instead of using neutral water, we were to use sodium hydroxide and water--basic water--what would happen is: the base would react with the carboxylic acid functional group (and we will look at this reaction next), and that would make an ionic compound.1001

    Now, that goes from being just a very, very polar functional group to an ionic functional group that is as extreme in polarity as you can get, when you have full charges.1024

    OK, so that makes it more soluble in water: ionic compounds love water.1035

    And so, what happens is: we can use base as a way to increase the solubility of a carboxylic acid by this chemical reaction it undergoes.1045

    The product of that acid-base reaction is an ionic, and therefore more water-soluble, carboxylate salt.1056

    Let's talk about the acidity of the carboxylic acid: it must be a significant physical property, if it is actually part of the functional group's name.1067

    If we go back to looking at an alcohol, an OH group that is just on an ordinary carbon change, that has a pKa somewhere around 18, and a carboxylic acid where that OH is attached to a carbonyl has a pKa somewhere around 5.1076

    That is 13 pKa units: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13; I don't even know what that number is--so many, many times more acidic by being a carboxylic acid OH instead of an alcohol OH.1089

    And so, we will talk about why that is in just a second; but right away, let's think about the choice of base.1109

    If you want it to deprotonate an alcohol, that is not a very easy thing to do; you have to use an extremely strong base.1114

    We use something like sodium hydride--a stronger base is needed, and furthermore, this is a base that is irreversible, because once you deprotonate, you would have the sodium salt here; and what is the other product you form?1121

    If you are using H- as your base, and it abstracts an H+, you end up with hydrogen gas.1143

    OK, so that was a way that we could make alkoxides.1150

    If we wanted to make an alkoxide, we would take an alcohol; we would treat it with sodium hydride--a very strong, irreversible acid-base reaction.1153

    Let's compare that to a carboxylic acid: most definitely, sodium hydride would effectively deprotonate a carboxylic acid, but we don't need a base that strong; we could use something like sodium hydroxide, and here a weaker base is OK.1162

    And, of course, we typically want to use the weakest base possible, because that is going to be cheaper; it is going to be easier to handle; and so on.1179

    OK, but that will give us the sodium salt; again, we get an O-, sodium +; this is called a carboxylate salt, when you have an O- attached to a carbonyl.1187

    Our other product here, when we use hydroxide, is water: that has a pKa on the order of 16, and so that wouldn't be strong enough to totally deprotonate an alcohol.1203

    But again, it very, very easily deprotonates a carboxylic acid; this reverse reaction is essentially nonexistent when there is such a big difference in the pKa's (16 compared to 5).1214

    OK, so one thing to keep in mind is that, any time you have a carboxylic acid exposed to basic conditions (things like hydroxide, alkoxide, something like that), you no longer have a carboxylic acid.1227

    You now have a carboxyl: we always need to keep that in mind--we can actually use that (like we just saw in the previous slide) for extraction purposes; that would be very handy.1242

    But we will also see some cases where we have to keep that in mind when we are doing our reaction mechanisms.1252

    OK, let's talk a little bit--since acidity is such a big component of a carboxylic acid's identity, let's talk a little bit more about these pKas.1258

    Why do we have this huge difference here?--can we explain that?--let's make sure we are clear on that.1267

    And, as usual, the way we are going to determine the difference, or explain that difference, is by looking at the conjugate bases.1274

    Let's look at alkoxide, versus a carboxylate, and see why it is so different getting to one versus the other.1282

    OK, if we have a carboxylate and an alkoxide, they both have a negative charge on oxygen, so they are both reasonable anions to have; oxygen doesn't mind having a negative charge.1293

    But one is so very different from the other, in terms of stability, and that is because this O- is attached to a carbonyl: that makes it an -ylic, and that makes it available for resonance.1303

    So, any time you have resonance delocalization, that is a good thing; any time you can delocalize the negative charge over two oxygens, that is a good thing.1320

    In fact, these two resonance forms are equivalent to each other; that is the best possible resonance stabilization you can have, because each of them is contributing 50/50 (they are contributing equally) to the overall hybrid.1328

    That is fantastic resonance stabilization.1339

    OK, so this has a...this is a resonance-stabilized conjugate base; we are really delocalizing the negative charge.1342

    That is a great thing: any time you can spread a negative charge out over multiple atoms, that is an excellent thing.1360

    That makes this less reactive.1365

    If you are more stable, that makes you less reactive; that makes him the weaker conjugate base: this is the less reactive, weaker conjugate base.1371

    The weaker conjugate base is the one that has the stronger parent acid.1384

    Is that what the pKa data told us?--yes, this was the pKa that was somewhere around 5--really low number--very, very good acid.1395

    OK, we compare that to the alkoxide: now again, oxygen doesn't mind having a negative charge, but it's all relative--we are just comparing this to a different O-; this one is resonance-stabilized; this one is not.1404

    So, this has no resonance; so there is nothing additional to stabilize that negative charge.1414

    There is way it can be delocalized over different atoms; OK, so if he is less stable (less stable--higher energy), that makes him more reactive; this is the more reactive, and therefore stronger, conjugate base.1421

    The stronger conjugate base has the weaker parent acid.1443

    And again, going back to that pKa, this is the pKa that was somewhere around 18.1452

    OK, so most definitely, you should have a good understanding of why it is carboxylic acids are such effective acids and what makes the carboxylate conjugate base such a stable species.1460

    OK, the take-home message that we have seen before and we are seeing again is that, if you have something that will stabilize the conjugate base, then that makes the acid a stronger parent acid.1472

    So always, what we are looking for is something to stabilize the conjugate base.1484

    Let's take a look at another example: let's compare acetic acid to trifluoroacetic acid; and the question is, "Which is a stronger acid?"1489

    Well, I don't see a difference in these two acids: they are both neutral; they are both stable; there is nothing unreasonable there.1499

    But, what we need to do is: we need to look at the conjugate bases, because those are charged species, and see if we can find a difference in their stability there.1504

    So, in other words, let's let each of these acids be an acid; let's deprotonate them; and of course, we are talking about the proton that is on the oxygen, that is always going to be the most acidic proton in a structure.1514

    Where we used to have an OH, now we have an O-; and the same thing over here--we used to have an OH; we have an O-.1528

    OK, now in this case, we are looking at a...they are both carboxylates (right?), so they both have the same resonance; so we need to find some other difference.1536

    The difference, of course, is that here we have hydrogens on the CH3; here we have fluorines, OK?--and what effect is that having?1548

    Well, what do you know about fluorine?--we know that fluorine pulls electron density toward itself; fluorine is electronegative--that means it pulls electron density toward itself.1558

    So, let's start by stating some facts here.1568

    We could say, "Fluorine is more electronegative than hydrogen," right?1571

    So then, we can say that fluorine withdraws electron density inductively--this is an inductive effect, meaning there is not a resonance form we could draw for this; we just use this arrow, showing that the electrons in these bonds are being pulled toward the fluorine--they are being pulled toward the fluorine, and therefore this carbon-carbon bond is being pulled, as well.1582

    OK, so those are the facts; here is the tricky part: is that a good thing, or is that a bad thing?1610

    Is that something that helps to stabilize this negative charge, or is it something that causes the negative charge to be destabilized?--that is the tricky part.1617

    OK, and let's think about what that negative charge means: a negative charge indicates to us that there is an excess of electron density; there are too many electrons around that oxygen.1626

    What are those fluorines doing?--they are pulling some of that electron density away.1636

    It kind of sounds like a good thing, doesn't it?--yes; it is delocalizing; it is helping moving and spreading it out through the molecule.1643

    OK, so this stabilizes the negative charge; that is a good thing.1649

    It delocalizes (right?): it puts some of the negative charge out on these fluorines.1665

    OK, so that means...let's call this one A, and B; so this is conjugate base A and conjugate base B; that is always a good idea, so that we can refer to things by name.1675

    So what we can say here is that conjugate base B is the more stable, and therefore less reactive, and therefore weaker, conjugate base.1690

    It is more stable, therefore less reactive, and it's the weaker conjugate base.1711

    Conjugate base B has the stronger parent acid.1715

    And that was our original question, right?--"Which is the stronger acid?"1728

    That was the...so B is the stronger acid.1731

    OK, something that stabilizes the conjugate base makes for a stronger acid; if we take a quick look at an energy diagram, and we compare the energies of A and B, they are relatively similar in energy; there is no big difference between A and B.1740

    But then, when we look at their conjugate bases, we see that conjugate base A is higher in energy than conjugate base B.1761

    The presence of those fluorines helps to stabilize it and lower the energy of that conjugate base; so B being deprotonated is an easier path than A being deprotonated; this is more favorable.1771

    Something that stabilizes a conjugate base makes the parent a stronger acid.1788

    We saw how resonance can do that, and here is an example of how inductive effects can do that.1795

    So, trifluoroacetic acid is a stronger acid than just ordinary acetic acid.1799

    Now, one more thing about inductive effects is that they decrease with distance.1806

    Because they are a through-bond effect, the more bonds it has to travel through, the less and less effect you see.1811

    For example, if you had a fluorine 10 carbons out from your carboxylic acid, the carboxylic acid wouldn't even know that the fluorine was there, and it would have no effect on the pKa, for example.1817

    Here is an example of some compounds that you can see that in: here we have carboxylic acid attached to benzene (this is known as benzoic acid).1827

    It is good to know some of these IPAC names, or a common name, for this carboxylic acid; we will see it a lot.1839

    Here we have some substituted carboxylic acids: here we have the fluorine in the para- position (this is called parafluorobenzoic acid); this is in the meta- position; this is in the ortho-position.1849

    OK, the benzoic acid itself has a pKa of 4.2, so what do you expect for these fluoro- substituted benzoic acids?--what do you think is going to happen to the pKa?1861

    We would expect these fluoro- substitutions to be more acidic; what does that do to the pKa?--it lowers the pKa.1873

    So, we expect them all to be lower than 4.2, and they are; but the one where this fluorine is really far away--very, very slightly lower: it's 4.1--just barely any difference at all.1880

    When it is meta-, it is 3.9, and when it is ortho-, it's 3.3; so almost 10 times more acidic, by having the fluorine here.1891

    This is quite far away from the O-; so it tells you that these inductive effects can be pretty powerful.1898

    They all have the same resonance; the carboxylate conjugate bases all have the same resonance; but it is these inductive effects that are affecting their pKas.1904

    Let's talk about the preparation of carboxylic acids: Where do they come from?--how can we get a carboxylic acid product?1916

    Well, because the carboxylic acid carbon is highly oxidized (it has 3 carbon-oxygen bonds), one way we can get there is by doing an oxidation reaction.1923

    We could start either with a primary alcohol or an aldehyde; both of these carbons already have a C-O bond, and they also have hydrogens that are capable of being lost to oxidation; so if we treat this with a very, very strong oxidizing agent, then we would expect that carbon to be fully oxidized to the carboxylic acid.1933

    All right, these are both two-carbon substrates, so we would get acetic acid as our product here.1956

    What are examples of strong oxidizing agents?--things like our Jones oxidation, chromic acid, sodium dichromate and H2SO4...KMnO4 permanganate and base is very good...1962

    OK, but notice: because we have base here, what is going to happen to the carboxylic acid product as it is formed?1974

    It will be deprotonated, and so, if you want the neutral product when you are all done, you have to do NH3-O+ workup; OK, that is just a little note on your basic reactions requiring acidic workup, if you want to get the neutral carboxylic acid product up.1982

    OK, the same thing for this oxidizing agent: this is known as Tollens reagent; when you use silver oxide, it also requires base, so we have to do an NH3-O+ workup in this case.1996

    This is an interesting reaction, because we use silver + to carry out the oxidation, and of course, the oxidizing agent itself gets reduced when it takes the electrons, and so it goes from silver + to silver 0.2007

    Well, silver 0 is silver metal, and so the Tollens test is a test for aldehydes.2021

    If you treat it with silver oxide, it will form silver metal, and the silver metal, if it is done just right, can plate itself out on the inside of the glass wall of the test tube, and you can get a mirror that is formed in this reaction.2028

    This is known as the silver mirror test for aldehydes, for RCHO, and the reaction involves oxidizing the aldehyde to a carboxylic acid.2044

    Of course, these qualitative tests are not nearly as widely used anymore, because we have spectroscopic techniques that can do a better job of quickly and easily analyzing our functional groups that are present.2059

    We can oxidize primary alcohols or aldehydes to get a carboxylic acid.2072

    We can also oxidize an alkene or an alkyne by doing an ozonolysis reaction; so the reaction of an alkyne with ozone totally breaks the carbon-carbon triple bond.2078

    All three carbon-carbon bonds go to carbon-oxygen bonds; so the product you get out is a carboxylic acid.2091

    We would get benzoic acid and acetic acid, in this case; so ozonolysis of an alkyne does that.2100

    Now, if we do ozonolysis of an alkene, if we do it with just an ordinary reductive workup, we would get out 2 aldehydes in this case--see how this double bond has a hydrogen at each position?2107

    We would get benzaldehyde and acid aldehyde, in this case; but we just learned that, if you had an aldehyde, you could take these, and you can oxidize them up to the carboxylic acid.2121

    So, you could use Jones oxidation or something like that, and you could get the carboxylic acid instead.2135

    OK, or we could go straight from here to the carboxylic acids, by doing ozonolysis, and instead of doing a reductive workup where you keep these hydrogens, you could do what is known as an oxidative workup, where instead of treating it with a reducing agent, you treat it with an oxidizing agent, like hydrogen peroxide, and then, all in that one pot, you go straight to the carboxylic acid.2142

    That is kind of handy: if you know you want the carboxylic product out, there is no need to reduce and then oxidize in a separate step.2167

    We can also use organometallic reagents to create carboxylic acids, using either organolithium or Grignard.2179

    If we treat those with CO2 (with carbon dioxide), we can form a carboxylic acid.2189

    Let's take a look at that mechanism: we have either an organolithium or the Grignard; we have an R- equivalent--that is a good nucleophile.2197

    And, if we take a look at the structure of carbon dioxide, we see a carbonyl here; so that looks like it would be a good electrophile.2208

    And so, we can have it attack the carbonyl and break the π bond; and let's take a look at what product that gives us.2218

    When we follow those electrons, look what we get.2229

    We get a carboxylate salt very close to being the carboxylic acid (right?)--after step 2, H3O+ will protonate our product, and we get a carboxylic acid out.2233

    That would be a great way of synthesizing a carboxylic acid; this is good for synthesis, because we just created a new carbon-carbon bond; we used a carbon nucleophile; we used a carbon electrophile.2249

    So, where the other ones, like the oxidations, use functional group in their conversions (oxidizing carbons have already existed), this is a way of introducing a new carbon and introducing that carbon as a carboxylic acid functional group.2259

    This is the new carbon-carbon bond that was formed.2273

    Let's see an example where this might come in handy: how about if we started with this alcohol, and we wanted to form this carboxylic acid?2283

    Now, when you compare your starting material and your product, you see: we had one; now we have two carbons; so this is a bond that we need to form, in this case.2289

    So, when we do our retro-synthesis, our retro-synthesis says, "What starting materials do I need?"2299

    Well, we recall that this is actually--this bond between a carboxylic acid carbonyl and the next carbon over--this is a bond we know how to form.2310

    We know how to make it, because we just saw that.2321

    Let's take a look at the two carbons involved in this reaction; we want these two carbons to come together; one of them must have been a nucleophile; one of them must have been an electrophile.2324

    The carbon is now a carboxylic acid; that carbonyl that was my electrophile--what did he look like before the nucleophile added?2335

    This was carbon dioxide: it was a carbonyl and another carbonyl.2345

    What nucleophile means--that means this methyl group was my nucleophile somehow; how did I make it a nucleophile?--I used a Grignard.2349

    The starting materials I need: I need methylmagnesium bromide, and I need carbon dioxide.2359

    If I had these two ingredients, I would be able to make this target molecule.2366

    That is a good plan: let's look back to see where we are.2371

    We are at methanol: we need methylmagnesium bromide; so let's think about the Grignard--how do you make a Grignard?2374

    You start with the alkyl halide, and you throw in some magnesium metal.2382

    So, what I will need to do is: I will need to convert this to methyl bromide (or methyl iodide if you want--any halide will do)--but we could use TBr3 to convert the alcohol to the bromide.2386

    Then, we can add in magnesium metal, which will insert itself there and give us the methyl-magnesium bromide.2398

    And then, we are going to take that Grignard, and we are going to react with carbon dioxide, but a Grignard reaction is never just "throw in the electrophile and you are done"; remember, we need to throw in the electrophile, and then we need to work it up.2406

    That is where this proton comes from; so this is always going to be a two-step procedure.2419

    Step 1 is carbon dioxide; Step 2 is H3O+; and work that up.2422

    It's very useful to use Grignard's and carbon dioxide in synthesis of carboxylic acids.2431

    Now, finally, another way that we can form a carboxylic acid is by starting with one of the carboxylic acid derivatives and converting it into a carboxylic acid.2440

    OK, we call this reaction hydrolysis; and if you take any carboxylic acid derivative (remember, most of them look like this, with a leaving group attached to a carbonyl, but remember, the nitrile was in this category too, and this reaction would work as well)--if you take these, and you react it with water plus some acid catalyst (this also works with base)--OK, when we do water and acid, we get a hydrolysis, and the product we get is a carboxylic acid.2451

    This is really what defines something as a carboxylic acid derivative: these are all compounds that, upon hydrolysis, give a carboxylic acid as a product.2480

    Now, you will either get the carboxylic acid, or if you use base here, what is going to happen in that carboxylic acid?--it will get deprotonated, so instead of getting the neutral acid, you would get the carboxylate salt.2491

    OK, but still, it's clearly just a proton away from being a carboxylic acid.2505

    What these all have in common, including the nitrile case, is: you are taking a functional group that has 3 bonds to heteratoms (nitrogen, oxygen, halogen, right?); with hydrolysis, you convert them to be 3 bonds to oxygen.2511

    OK, so hopefully then, even the nitrile--you can see we have gone from three C-N bonds to three C-O bonds; that is defined as being a hydrolysis.2529

    Let's look at an example of an ester: that is kind of a nice derivative to start with.2541

    The ester here has an O-R group attached to the carbonyl.2547

    Let's see that reaction with sodium hydroxide and water.2552

    Now, remember, I have a little H3O+ here at the end; we need that, because I want to look at the product where I get the neutral carboxylic acid.2557

    Now, this is another example of an acyl substitution: I hinted that that was going to be the sort of mechanism we will see for carboxylic acids and their derivatives.2566

    And overall, it is going to be a mechanism where we do addition and elimination--addition of our water nucleophile and elimination of our leaving group (our leaving group is right here--we are going to be losing methanol in this reaction).2574

    OK, and let's do our mechanism: we have the ester; we have hydroxide; the ester, as usual with our carbonyls, is going to be our electrophile; the hydroxide is going to be our nucleophile.2587

    What is going to happen?--well, the hydroxide is going to attack the carbon and break the π bond.2599

    So, as usual, we are going to get a nucleophilic addition to the carbonyl, which gives us an O-.2606

    Add in our lone pairs; so we add into the carbonyl, and then where does that bring us?2616

    Oh, that brings us, actually, to an intermediate we have seen--introduced in this lesson: we have a tetrahedral carbon, where at least two of the groups (in fact, three, in this case) have a lone pair, and one of them has a charge--we call this a charged tetrahedral intermediate.2624

    What happens when you have a charged tetrahedral intermediate?--it is going to collapse.2646

    This first step was our addition step; we had addition of our nucleophile into the carbonyl; and our second step here is our elimination step, where we eliminate our leaving group.2655

    What we are going to do here is: we are going to do two arrows to do this elimination; we call this collapse of the CTI, and it is where the O- re-forms the carbonyl and kicks that leaving group out.2668

    Our product is going to be our carboxylic acid.2689

    Now, we just kicked off OCH3-; we just lost that group; and we have our carboxylic acid product addition-elimination.2694

    OK, however, let me ask: are we done here--is this our final product?2705

    We just formed a carboxylic acid; what kind of reaction conditions do we have?--we have base: we have sodium hydroxide.2710

    This is not...we are not yet done here, because we have a carboxylic acid (let me redraw this down here)--we have an acid in the presence of base, and what I hinted is that every single time you see a carboxylic acid and you are around base, you will have a deprotonation.2718

    That is a very favorable reaction, so what is going to happen is: we are going to deprotonate...very much favored in the forward direction here...and we will get the carboxylate.2745

    The carboxylate salt is formed.2762

    That is our final product in this hydrolysis reaction; our base promoted--we don't call it catalyzed, because in this final step, we actually consume an equivalent of our base; we don't get it back anymore, because this reaction is so favored in the forward direction.2768

    OK, and then finally, now you can see why we need this step 2 H3O+: we can protonate our carboxylate and get our carboxylic acid as our final product.2788

    And, in fact, this deprotonation here drives the equilibrium forward, because (you can see) every step that we are doing is reversible; we get a hydroxide added in, and then it can kick back out.2805

    Forward-reverse, forward-reverse; every one of these steps is reversible, and they are in equilibrium; but this one last step, when you form the carboxylic acid--this deprotonation is essentially irreversible.2824

    That is what keeps the reaction moving forward, moving forward, moving forward, and affecting that overall hydrolysis.2834

    Now, let's think about this overall substitution reaction that we just did here.2842

    OK, in this case, our nucleophile was hydroxide that we were bringing in, and our leaving group was methoxide.2850

    Now, that is kind of interesting, because we have never seen an example where an alkoxide was a leaving group.2859

    That is because, in the mechanisms we have seen up until now, an alkoxide was not a permissible leaving group; so for example, if we wanted to an SN1 or an SN2, or E1 or E2, for that matter, but if we wanted to do a substitution mechanism that is unimolecular or bimolecular, something like this--if we thought of this hydroxide coming in and then just kicking out methoxide as a leaving group, that would never happen.2869

    That is an impossible substitution mechanism.2898

    We could only do that substitution if we have an excellent leaving group, like chloride, bromide, iodide, halide, or maybe a tosylate.2902

    OK, so we have never seen that as a leaving group; but it is an OK leaving group for collapse of a CTI; so if we have this mechanism, where we have an O- on the same carbon as that methoxide (remember, we have a tetrahedral carbon--that is our definition of a CTI: a tetrahedral carbon with 2 groups with lone pairs), then it is possible for that methoxide to kick out, because it is not just leaving on its own--it is being pushed out.2909

    So, we have this push-pull phenomenon going on; and using the two arrows helps you to see that it is not just methoxide dropping off on its own (kind of like an SN1 mechanism might be).2940

    It is only dropping off because you have this other group that is capable of pushing it out.2955

    That gives us a carbonyl, and that gives us our methoxide leaving group.2963

    OK, the driving force for this reaction--the reason that we can use methoxide in this case (because methoxide is pretty unstable--that is pretty hard to be on its own)--the reason it is OK is because we have formation of a carbonyl.2968

    What makes collapse of a CTI great--and again, you can see if you use those two arrows--is a pushing out of that leaving group; it gives a carbonyl--forms a carbonyl--in the process.2987

    And a carbonyl is a nice, strong, stable, resonance-stabilized functional group; so any time we can form a carbonyl, that is always going to be a good mechanism.2998

    Now, this base-promoted ester hydrolysis (that is the reaction we just studied) is called a saponification reaction; it is described as a saponification reaction because it literally can be used to make soap.3010

    Now, if you think historically--let's just stop for a moment and think about that word--historically, if you wanted to make soap (or in many parts of the world, where people make their own soap), the way you do it is: you take animal fat, and you treat it with ashes from a fire, and you mix it up with water, and you cook it--you boil it.3023

    The solution you get out is a soap solution.3043

    Now, a couple questions: "How is this working?" and also "Who in the world thought of this as a good idea to wash clothes?"3046

    The fact that you are going to take some bacon grease and throw it in some hot water, grab a handful out from the fire (some of the ashes), throw it in there, and cook it up--why would you ever think that would be a good idea to wash your clothes in?3055

    This has always kind of fascinated me.3065

    And the theory on how this evolved over time is that the women who were washing clothes would maybe have a bucket of water, or a little area of water (little puddle of water) that they were using; and they would maybe use a piece of wood to agitate their clothes as they were washing in the water.3068

    What they noticed was--after a while, after washing their clothes for a while, your washing solution would become more effective.3088

    It would be easier to wash clothes at the end of the week than it was at the beginning of the week.3101

    And so, what was happening was: the wood ash was coming from the wood that they were using to agitate, and the animal fats were coming from the clothes that we were washing.3106

    We are introducing more fats into the solution.3119

    So, that is when they kind of decided, "Hey, rather than wait for our soap solution to get good by the end of the week, or the end of the month, let's just add this stuff in the beginning"; and you would make out a soap solution.3122

    Now, as organic chemists, we could take a look at the structures of these components in these molecules to see what is going on.3134

    It turns out that animal fats are actually esters, and the wood ash is a source of sodium hydroxide.3140

    And so, this is the reaction that is taking place: we get a hydrolysis reaction to take place, and what is the product when you take an ester and you treat it with sodium hydroxide in water?3149

    Well, you do a hydrolysis, and you get the carboxylic acid as usual, but because it is in base, you don't get the carboxylic acid; you get RCO2-; you get the carboxylate salt.3162

    Now, how does a carboxylate salt act as a soap, and what do the structures of these molecules look like?3182

    Let's take a look at that.3188

    The saponification reaction takes a triglyceride (this is the structure of a triglyceride--you could call it a lipid or a fat or an oil); glycerol is the tri-ol, with three carbons, with an OH on each carbon; if you mix those with carboxylic acids, these are known as fatty acids, because they have really, really long carbon chains on them that make them fatty--make them hydrophobic.3192

    These acids can be either saturated, meaning they have as many hydrogens on them as possible--there are no double bonds; or they could be unsaturated.3218

    And of course, you have heard of monounsaturated fats, polyunsaturated fats, saturated fats--these all have to do with the structures of those carbon chains that are part of the triglyceride structure.3227

    We take this triglyceride--these are the animal fats that we are starting with; we treat this with sodium hydroxide and water; what we get is addition-elimination.3239

    We get a substitution reaction, where hydroxide comes in and kicks out this alcohol on each of these ester groups.3248

    We get back a molecule of this glycerol (that is your leaving group in each case), and then these carboxylic acid groups that are freed get deprotonated, and we get these carboxylate salts--again, these long carbon chains either have double bonds, maybe, or not.3255

    Now, if you take a look at this carboxylate salt, if you have a very, very long carbon chain, we would describe that as being hydrophobic.3274

    It is a nonpolar carbon chain, so that doesn't like water.3285

    And here, this carboxylate salt is highly polar; in fact, it is ionic; so you have this hydrophilic part.3290

    If you put those into water, what happens is: they congregate into something known as a micelle.3297

    They are going to arrange themselves in water into a sphere, where the outermost part of the sphere is coated with the hydrophilic heads (the ionic part), and all of these hydrophobic tails are buried inside of the sphere to minimize their contact with water.3303

    That is called a micelle; this is a very nice model of a micelle--of course, just a toy, but it works very nicely as a model.3321

    You can imagine each one of these little rubber strings as being one of those carboxylate units, and so the outside is ionic, and it's charged, and so there is a very positive interaction with water; the inside is all of our hydrophobic, greasy long carbon chains.3329

    Now, how does this work to clean things?3348

    Well, I have my soap solution with all of these micelles floating around in it; now if I take my clothing, and I agitate it (put it in a washing machine or scrub it on a scrub board or something like that), the grease and oils that are dirty on my clothes are going to make their way onto the inside of this micelle, where it is going to be very nicely dissolved by the interior of the micelle, which is hydrophobic and nonpolar.3350

    The grease works its way inside of this; we describe it as being emulsified when the grease kind of breaks up and gets trapped inside of these micelles.3379

    And now, when I wash my clothes with fresh water, these micelles get washed away, and our grease gets washed away at the same time.3387

    That is kind of how soaps work; now, you still could make soap using animal fats (and like I said, around the world, they still do that), but we can also have synthetic detergents that have this same general structure.3395

    It is not necessarily a sodium carboxylate salt here, because that has some problems making soap scum with hard water and so on.3409

    We can have different kinds of ionic (or very polar) head here, and various structures for the tails as well; and that is how we end up with a wide variety of soaps and detergents that all have very different cleaning powers.3419

    OK, back to the real world, then: that was the base-promoted ester hydrolysis mechanism; let's take a look at that same reaction, but an acid.3436

    We have an ester here, and now we are using H3O+.3445

    And in an acid-catalyzed mechanism, we can't have any strong bases around; so there are not going to be any negative charges, like we saw in the base-promoted one with hydroxide.3451

    What do you think our first step should be in an acid-promoted reaction--acid-catalyzed reaction?3462

    I think I should probably protonate something somewhere, because I have acid around; and that is where our carbonyl is going to come into play.3467

    I could just use HA to represent H3O+; our first step is going to be to protonate the carbonyl.3474

    Now, you could protonate down on this oxygen, and that certainly will happen; but remember, every protonation is reversible, so that is not something that is going to lead your products; so that is not something we are going to concern ourselves with right now.3484

    But let's protonate the carbonyl; and by doing so, we take a carbonyl (which is a good electrophile), and we add a positive charge to it; we make it even more electron-deficient.3496

    This is now a great electrophile--a super-electrophile.3507

    So, I'm going to look around for a nucleophile to add; what nucleophile is there?--of course, there is water; so H3O+ means I have H2O and some strong acid, HA.3513

    Sometimes you will see it drawn this way; sometimes you might see it drawn this way; but either way, you certainly have water around to be your nucleophile, and that water is going to attack the carbonyl and break the π bond.3524

    It gives me an OH up here, and this oxygen from water still has the two hydrogens on it, and what else?--how many lone pairs?3545

    It has just one lone pair, because the other lone pair is right here now; it is being shared as this covalent bond, so it has one lone pair left; and that looks like a 1, 2, 3, 4, 5 oxygen one...6...looks like an O+.3554

    I am going to protonate, and then attack, and then what do I do last?--I need to get rid of that positive charge.3568

    I am going to deprotonate.3578

    Protonate, attack, deprotonate: this pattern we are going to see again and again and again.3584

    I can use water to come back in, or I can use A-, like I had in that first step--something to deprotonate.3588

    What I have done so far is: I have done my addition of my nucleophile.3604

    Remember, I want to do a substitution; so I want to add in my nucleophile, and then what do I want to do?--I need to eliminate my leaving group; I need to get rid of my leaving group.3612

    Who is my leaving group going to be?--it is going to be this methoxy group.3622

    How do I make it a good leaving group?--an acid--how do I make it a good leaving group?--I need to protonate it.3627

    I bring my HA back in and protonate the methoxy group to be a good leaving group; now I have a good leaving group, and what else do I have?3636

    How would you describe this intermediate?3656

    It looks like I have a CTI; I have a charged tetrahedral intermediate; I have a tetrahedral carbon, two or more groups of lone pairs, one of them is charged; I am in the perfect situation to do collapse of a CTI.3662

    OK, remember: two arrows to do this collapse; so in other words, don't just lose the leaving group on its own; have one of these other groups.3677

    It actually doesn't matter which one you use; have one of these other groups push it out.3685

    That is the whole point of being a CTI and doing carbonyl mechanisms: you form the carbonyl as our leaving group leaves.3690

    OK, now, what leaving group did I have?--my methanol just got kicked out, so that is one of the products of my reaction.3698

    Notice: we need to have methanol as a leaving group--we can't have methoxide, in this case, because methoxide is a very strong base and is not compatible with acidic conditions.3705

    Remember: no O- (or CH3O-, in this case) in acid.3714

    I need to protonate first; that gives me a nice CTI; that gives me a good leaving group, and now I can collapse.3722

    OK, and now, when I do that with my two arrows, look how close I am; all I need to do is deprotonate up here, so I can use water to come back in, or I could use A- (I keep switching back and forth--sorry).3727

    I used HA down here, so now I could use A- to come in and deprotonate, and I'm done; I have done my hydrolysis of an ester to give a carboxylic acid.3739

    It is going to be common that acid-catalyzed mechanisms are going to be significantly longer than the base-catalyzed ones (or base-promoted ones); so the base ones are good to work on initially; get the hang of it; understand the addition-elimination and the use of CTIs.3754

    In those, we are working on negative charges; in acid, we are going to have positive charges; and the same general idea is going to happen.3769

    At some point, we are adding in our nucleophile; at some point, we are losing our leaving group; there are just a lot of other protonations and deprotonations mixed in to avoid our negative charges.3775

    Let me just point out: we have seen the acid-catalyzed; we have seen the base-promoted; I want to point out that one of those is required (some sort of catalysis is required--either acid or base conditions) in order for this hydrolysis to take place.3787

    OK, we cannot take a neutral ester (which is a weak electrophile) and neutral water (which is a weak nucleophile) and expect the two to come together.3801

    If we tried that...let's try it: just have neutral water attack a neutral ester; look at what we get.3815

    I now have an O- up here; and down here, I have an O+; OK, that is when you know you have made a mistake in a mechanism, because I can't have a strongly basic O-, ever, in the same sort of reaction conditions that I have a strongly acidic O+.3824

    There is no O- and O+ in the same mechanism: that is good to keep in mind, and that is good to help guide and help you pick up when you have maybe made a mistake.3845

    This is not going to happen; so instead, how does it work?3859

    Well, in basic additions, you increase the nucleophilicity of something; so how does this get adjusted in base?3862

    You don't have water attacking; you have a strong nucleophile, hydroxide, attacking.3872

    OK, then you have an O- that attacks; you have another O-; and so on.3880

    OK, how about an acid--how would I change this in acid to make the mechanism acceptable?3884

    Well, in acid, our very first step is protonating the carbonyl; so in acid, we don't have a neutral ester; we have a protonated ester.3890

    We have a protonated carbonyl, which is an excellent electrophile; so in base, you find negative charges and strong nucleophiles; in acid, you find positive charges and strong electrophiles.3902

    We are going to see this pattern coming in again and again and again; so this is an excellent time for you to get used to that.3916

    Now, let's just take a look at a nitrile example, because the nitrile looks a little different than the ester.3924

    All of the other carboxylic acid derivatives would have essentially the same mechanism as the ester, but the nitrile looks a little different; so let's see how we would handle that.3929

    Now, first of all, when we do a hydrolysis on an amide, there are two possible products you can get.3937

    If you do just a mild hydrolysis, we can replace two of the C-N bonds with C-O bonds, resulting in an amide product.3945

    We would describe this as being partial hydrolysis; and if we wanted to have more vigorous conditions (where we have, let's say, H3O+ and heat), we wouldn't stop at the amide; we would continue doing a hydrolysis of the amide.3956

    We know the amide is a carboxylic acid derivative, as well, right?--so it can also undergo hydrolysis; so we have addition-elimination, addition of water and elimination of the nitrogen leaving group.3973

    We would ultimately get a carboxylic acid product, OK?3983

    But this is kind of handy, because this is another way that we can create an amide (we will see down the line): by partial hydrolysis of a nitrile.3986

    Let's see if we can do this mechanism: this mechanism is just like the ester--very similar to the ester.3993

    We have already something on how to do this transformation; but let's see how we can go from a nitrile to an amide--that is a little less intuitive.4003

    We have acetonitrile (this nitrile); we have H3O+; our first step, I am thinking, is going to be to protonate, because we have an acid.4015

    Let's write that out: so protonate first; and where do we protonate?--well, the best course of action is to treat the nitrile, the C-N triple bond, just like it was a carbonyl.4033

    Do exactly what you would expect a carbonyl to do: I'm going to take a lone pair on nitrogen and protonate.4045

    Just like I would protonate a carbonyl, I can protonate a nitrile.4055

    And, just like protonation of the carbonyl made it a great electrophile, protonation of the amide also makes it a great electrophile, so we can look around for a nucleophile--we'll have water here, in this hydrolysis reaction, as our nucleophile.4061

    How are they going to react?--well, just like they would for a carbonyl: this oxygen is going to attack the carbon and break the π bond--totally analogous to a carbonyl.4077

    This oxygen still has two hydrogens on it, and a lone pair, so it's going to be an O+; and we now have a double bond between the carbon and the nitrogen, instead of a triple bond.4092

    OK, so what do we do?--we protonated, and then we attacked, and now we can deprotonate.4106

    The same pattern we have seen again and again for acid-catalyzed: protonate, and then attack, and now we can bring water back in as our base and deprotonate.4120

    OK, well, this doesn't seem like we are a lot closer, perhaps, but let me show where we are and think about where we are going.4137

    The initial product--the first intermediate product that we get in this hydrolysis is going to be the amide.4147

    Let me draw the amide (an upside-down amide); let's see if you can now think a little more clearly and identify what it is we have to do.4156

    This is a double bond with an OH here, and we are converting that to a carbonyl.4170

    OK, this structure is kind of like an -enol structure, which you may or may not have seen yet in a keto-enol tautomerization.4181

    It is a very similar mechanism; what we need to do is tautomerize--I'll just put this in parentheses, because you may not have seen that topic yet for ketones and aldehydes.4194

    But either way, when we compare these two structures, what we see is that here we have an NH, and now we have NH2; so one thing we have to do is--we have to protonate here.4207

    All right, at some point we have to protonate here, and down on the oxygen we have an OH, and it ends up being just an oxygen.4219

    So another thing we need to do is: we need to deprotonate here.4226

    It turns out that those are the exact two steps that we have to do for the remainder of this mechanism: we have to protonate and deprotonate, because we are in acidic conditions.4234

    Just like, up here, we protonated first, we are going to do the same thing here.4245

    We are going to protonate first, and then we are going to deprotonate second.4249

    How can I protonate this nitrogen?--well, you can think of using the lone pair, but our mechanism is going to be a little cleaner if we use the π bond.4254

    I can bring in another equivalent of H3O+ and protonate the π bond.4265

    Just like protonating the alkene, you break the π bond; you add a proton to one atom; and you get a positive charge on the other atom.4281

    And so, I protonate to get a carbocation; that was step 1.4291

    Step 2: I need to deprotonate--let's look at where we are and where we have to go--do you see how close we are?4295

    Let's bring water in as our base and grab that proton; and instead of having these electrons go and sit on the oxygen, it's going to be an O- and a C+.4304

    I'll go straight to the better resonance form, where those two electrons go to be a π bond; and we are done.4314

    We have formed an amide.4322

    OK, so we start out similar to what we would do for a carbonyl: protonate, attack, deprotonate; OK, but then, the second step is a conversion of one structure to another structure, and knowing where you are headed is really the key to getting this mechanism down correctly.4326

    OK, now the conversion of the amide to a carboxylic acid--we'll just say et cetera--that is going to be the same analogous one as the ester: we are going to do addition of the water and elimination of the nitrogen leaving group, in this case.4342

    Now, what is really cool about having a nitrile and knowing that a nitrile can be converted to either an amide or to a carboxylic acid is: we can use this--we can exploit this in synthesis, because cyanide is (there is a little lone pair here, too) a good nucleophile.4361

    There are strategies to get the nitrile functional group into a carbon chain; so let's see an example where that might come in handy.4379

    We have a 3-carbon chain here, and we want to convert it to this new compound; we still see our 3-carbon chain, but we see that there is this new carbon that is added on, and we need to synthesize that.4389

    OK, now let's think about our retrosynthesis: what starting materials do I need?4405

    There are actually a few different approaches we can have for this.4412

    One of them would be the nitrile that we just saw; so one approach is--we just saw that, where you now have a carboxylic acid, that could have come from a nitrile.4416

    In other words, if I had this nitrile, I could do a hydrolysis to get this carboxylic acid product.4430

    OK, so that would be a good strategy; now, we have to do this disconnection and ask ourselves, if we wanted these two carbons to come together and react, how could we do that?4437

    One of them must have been a nucleophile; one of them must have been an electrophile.4448

    Well, what we are remembering is that cyanide is a good nucleophile; so this certainly was my nucleophile, but that means this carbon was my electrophile.4452

    Somehow, I have to make that carbon electrophilic.4461

    Well, I'm starting with isopropyl chloride; I am starting with a leaving group in that position; it is already electrophilic.4464

    I think I have done enough planning here to think about my synthesis; so I can go ahead and do my transformation.4471

    I think my first step is to treat this alkyl halide with sodium cyanide to do an SN2 mechanism.4478

    That will replace the leaving group with the cyano group.4487

    And once I have the cyano group, now I can convert it to the carboxylic acid by hydrolysis; I want to trade those C-N bonds for C-O bonds; that is hydrolysis.4494

    H3O+...remember, some heat is required, because you want it to not stop at the amide; we want it to go all the way to the carboxylic acid: that is kind of a forcing reaction.4504

    OK, so nitriles are very handy this way, as a way to synthesize carboxylic acids.4514

    One last look at this problem: there is another strategy that we can think of; we have actually seen this as another way to make carboxylic acids--it would be exactly this disconnection, as well.4520

    What if we asked about these two carbons right away?--think about, instead of doing a functional group in a conversion right here back to a nitrile--what if we did a disconnection right away and asked about these two carbons?4533

    Which one could have been a good nucleophile?--which one was an electrophile?--what reaction have we seen that comes together and forms that carboxylic acid?4547

    How about if this carbon was my electrophile--what would that electrophile look like--a carbon with two oxygens?4559

    We could have carbon dioxide as an electrophile; what nucleophile would react with carbon dioxide to give this target molecule, then?4567

    How about if I had a Grignard as my nucleophile?--then that would react with CO2, and it would give this target molecule exactly.4579

    OK, so that is another approach that we can take; let's see how that would look.4589

    Well, we are starting with a chloride; I know, with a Grignard, we usually think magnesium bromide, but remember: a Grignard can be any halide, so we don't have to change that.4592

    We could just throw in our magnesium right away and make the magnesium chloride Grignard.4601

    Now, I have a good nucleophile; what did I want to do with that nucleophile?--I want it to react with the carbon dioxide.4610

    Remember, that is a two-step process: first, I could add in carbon dioxide; second, I could do an H3O+ workup to protonate; and so, this would give another strategy.4617

    In this lesson, we have been introduced to carboxylic acids, looked at their acidity and their other physical properties, and then we have also seen different ways to synthesize carboxylic acids.4627

    We looked at oxidation reactions; we looked at Grignard reactions to form them; and then, we looked at carboxylic acid derivative hydrolysis as another way to form carboxylic acids.4639

    We studied the mechanism of that hydrolysis reaction, and in the next lesson, we are going to look again at these carboxylic acid derivatives and think about "What reactions do they undergo?" and "How could we synthesize each of those functional groups?"4651

    I look forward to seeing you then; thanks for visiting Educator.com.4667