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Dr. Laurie Starkey

Dr. Laurie Starkey

Alkenes

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 (20)

1 answer

Last reply by: Professor Starkey
Wed Apr 29, 2015 11:38 AM

Post by Jinhai Zhang on April 28, 2015

Dear Prof.Starkey:
In your cyclohexanol example, if it is five carbon ring, under H2SO4, we have ring expansion, don't we? Do you have a lecture about ring expansion?

1 answer

Last reply by: Professor Starkey
Wed Dec 10, 2014 10:32 PM

Post by Parth Shorey on December 10, 2014

I understand you said that for OH to be a LG is to have a strong acid, but I'm still confused if that were to apply to Sn1/Sn2 reaction. How does a HCL work doing a back attack, like what happens to the Hydrogen. I just need to see a detain mechanism steps. The elimination I get because you have already showed us that.

1 answer

Last reply by: Professor Starkey
Wed Dec 10, 2014 10:33 PM

Post by Parth Shorey on December 10, 2014

At 19:46 would H2CrO4 be a good dehydration of the alcohol?

1 answer

Last reply by: Professor Starkey
Sun May 12, 2013 7:23 PM

Post by Sitora Muhamedova on May 12, 2013

Professor, Sn2 favors 3 degree, how come 1 degree reactions can be favored, and also, if Carbon 1 degree is favored by E1 reaction why would not it be appropriate to imply to our reaction with Bromide?

1 answer

Last reply by: Professor Starkey
Tue Oct 23, 2012 8:28 PM

Post by Meshari Alabdulrhman on October 20, 2012


Hi
Dr.Starkey

would you please explain more how to determine reagents and solvents in each reactions.?

1 answer

Last reply by: Professor Starkey
Sat Jan 21, 2012 1:03 PM

Post by Jason Jarduck on January 19, 2012

HI

Dr. Starkey,

Would you be able to show the individual 2-methyl-1-butene products.For reactions with HBR with CH2Cl2, Eto-K+, Br2, HBR with roor, NBS with RooR, BR2 please. YOU HAVE GREAT LECTURES I USE THEM FOR STUDYING FOR EXAMS!!!!
Thank you

1 answer

Last reply by: Professor Starkey
Wed Dec 28, 2011 11:33 PM

Post by Rohan Shah on December 14, 2011

Hey Dr.

Can you show the mechanism for treating an alcohol with phosphorous oxychloride?

1 answer

Last reply by: Professor Starkey
Wed Nov 30, 2011 11:12 PM

Post by Anahita Behshad on November 26, 2011

I was wondering if there is sth wrong with these videos,,,I used to watch these with no problem, but now these organic chem videos stop working after few minutes...I tried other videos in bio /math section but didn't have any problem with them :(

1 answer

Last reply by: Professor Starkey
Sat Nov 5, 2011 3:50 PM

Post by Jamie Spritzer on November 1, 2011

in 28:53 wouldn't the SN1 be major, since the carbon is secondary?

1 answer

Last reply by: Professor Starkey
Wed Apr 6, 2011 11:23 PM

Post by Billy Jay on March 23, 2011

Hi Dr. Starkey. I have two questions:

Are H2SO4, HClO4, HNO3, and HClO3 the only Strong Acids that would be limited to E1 (instead of SN1). The reason I ask is because of the remaining 7 strong acids (HCl, HBR, and HI) all have a conjugate base (weak base) that acts as a strong nucleophile.

Also, at around 33:00 you react a primary Alcohol with H2S04 and explain that it would most likely undergo E1 and re-arrange to a tertiary carbocation. Is it also possible for an E2 product to form as well? Is the reason you excluded it because in this case, E2 would be a very minor product since the primary substituted alcohol is unfavorable for E2?

Thank you.

Alkenes

Draw all the products and select the major product for this reaction:
  • Alkene is more stable if more alkyl groups are attached
  • includegraphics*Ochem-12-1b.jpg
Draw the product(s) formed from this reaction:
  • includegraphics*Ochem-12-2b.jpg
  • includegraphics*Ochem-12-2c.jpg
includegraphics*Ochem-12-2d.jpg
Draw all the products and select the major product for this reaction:
Draw all the products and select the major product for this reaction:
Draw all the products and select the major product for this reaction:
Draw all the products and select the major 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

Alkenes

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.

  • Intro 0:00
  • Alkenes 0:12
    • Definition and Structure of Alkenes
    • 3D Sketch of Alkenes
    • Pi Bonds
  • Alkene Stability 4:57
    • Alkyl Groups Attached
    • Trans & Cis
  • Alkene Stability 8:42
    • Pi Bonds & Conjugation
    • Bridgehead Carbons & Bredt's Rule
    • Measuring Stability: Hydrogenation Reaction
  • Alkene Synthesis 12:01
    • Method 1: E2 on Alkyl Halides
    • Review: Stereochemistry
    • Review: Regiochemistry
    • Review: SN2 vs. E2
  • Alkene Synthesis 18:57
    • Method 2: Dehydration of Alcohols
    • Mechanism
  • Alkene Synthesis 23:26
    • Alcohol Dehydration
  • Example 1: Comparing Strong Acids 26:59
  • Example 2: Mechanism for Dehydration Reaction 29:00
  • Example 3: Transform 32:50

Transcription: Alkenes

Welcome to Educator.0000

Next we are going to talk about alkenes; there is actually a couple lectures we are going to have on alkenes.0002

We will start by looking at the structure of alkenes and the synthesis of alkenes; an alkene is defined as a molecule containing a carbon-carbon double bond.0006

When we look at the structure of a carbon-carbon double bond, we remember that it is a planar structure; each of these carbons has sp2 hybridization; that requires a trigonal planar geometry.0018

Connecting the two carbons are two bonds; we would describe these bonds as one σ bond and a π bond.0041

The way a σ bond is made is we join the hybrid orbitals on each carbon; this is an sp2 overlapping with an sp2 hybrid orbital.0055

For the π bond, the way we form a π bond is have a p orbital on each of these carbons and that is overlapping to form the π bond.0070

This model has a very nice picture of what an alkene looks like; here in the gray, we see the σ bonds; they are all planar.0077

On each carbon, each sp2 hybridized carbon, we have a p orbital; remember that is the dumbbell shape type orbital.0089

It is overlap of the top half of that orbital and the bottom half of that orbital that comprises a π bond; a π bond is a cloud of electrons above and below the plane of the molecule.0095

We could describe the π bond as being the overlap of a p orbital and another p orbital.0107

If we want to do a 3D sketch of this molecule, one way to draw it is to draw all the σ bonds in the plane; that is certainly an easy way to draw all the σ bonds.0114

Trigonal planar means these bond angles are about 120 degrees; but then our 3D sketch should also show the π bond and where the π bond is.0127

If the molecule is in the plane, then the π bond is perpendicular to that plane, sticking straight out and straight back.0135

We can sketch that as maybe a wedged and a dashed lobe, a wedged lobe and a dashed lobe, one on each carbon; then we can show some overlap at the front and back.0142

What we need to show is that the p orbitals are perpendicular to the sp2 plane; or orthogonal; we need to show that they are perpendicular.0153

Actually another way that we can draw this molecule is to draw it so that the p orbitals are in the plane, the π bond is in the plane.0164

We could draw our p orbitals nicely shaped and our π bond, again, top and bottom shows overlap.0174

But when we do that, what happens to the hydrogens?--if there are hydrogens here or the σ bonds, whatever they are attached to?0181

The σ bonds are now--these two are projecting out toward you and the others are pointing back; the rest of the molecule is now perpendicular to the plane.0186

We need to show them as a dash and a wedge; when we go to draw this, what we do is we tilt it just a little bit so you can see the wedged bonds and the dashed bonds as well.0197

You want to make sure you use the same angle though; either tilt it up a little or tilt it down a little; you don't want to try and twist the molecule and draw it like that.0206

Here I drew both wedged bonds pointing down toward the bottom of the page; that would be an acceptable drawing.0215

Either of these 3D sketches look really good as a way to draw an alkene, a carbon-carbon double bond.0222

What else do we know about π bonds?--we've seen a little picture of them; we should also know that π bonds are higher in energy than σ bonds.0229

The p orbitals are higher energy, that are coming together to form those π bonds; that is going to make them more reactive.0238

We are going to see lots and lots of reactions that break π bonds and all sorts of reactions of alkenes that we will talk about in our next lecture.0245

Also, we want to note that π bonds are electron rich; they are a good source of electrons; those two electrons are fairly loosely held; they are fairly available.0255

What are some things we associate with electron rich species?--they could be a nucleophile; what does it mean to be a nucleophile?0263

That means you can react with an electrophile; we will see a lot of reactions of alkenes with electrophiles.0269

It could also be a base; what does it mean to be a base?--an acid is something that donates a proton; a base is something that accepts a proton; in other words, it can be protonated.0278

Many of our mechanisms for alkenes, we are going to start with reaction with an acid and our very first step is protonation of that π bond.0290

We should also review some things that make alkenes stable; some of the things we've already seen before; but some other things that we want to know.0299

One feature is that an alkene is more stable if it has more alkyl groups attached to it; more carbon groups, the better.0309

If we take a look at this carbon-carbon double bond, it has a possibility of having four alkyl groups attached.0318

In this case, we have one, two, three of those positions filled with alkyl groups; we describe this as being tri-substituted.0328

We know that is going to be more stable than... for this alkene, our carbon-carbon double bond is here; how many alkyl groups do we have attached?0340

We have just one and two carbon groups attached here; this we could describe as di-substituted; it is less stable; a di-substituted alkene is less stable than a tri-substituted alkene.0348

Another way you could describe these two particular alkenes is you could say that this one is internal to the carbon chain while this one is terminal.0360

The second one is terminal; it is at the end of a carbon chain; that is also not a good place for a double bond to be.0369

We can look for features like that to determine whether or not our alkene is more or less stable; we can also look for the relationship of the groups that are attached on a double bond.0374

For example, if we have a di-substituted double bond, we know that the... we could have a cis arrangement or a trans relationship.0388

This cis one is when they are both facing on the same side of the double bond; trans is what we call it when they are on opposite sides of the double bond.0397

The trans is more stable; that is because by forcing these two alkyl groups in the same direction, they have some steric strain, some steric hindrance there.0404

There is some more crowding; cis is going to be less stable than trans.0417

The exception is when we have a double bond within a ring; if we take a look at something like this--cyclopentene or cyclohexene.0421

In order for these two groups on the double bond to connect in a ring, they actually must be pointing in the same direction on the double bond; it has to be the cis conformation.0432

For small rings like these, it is cis only; it is possible to have trans if you get to a larger ring.0442

It is possible if it is seven; that is still pretty unstable; but as soon as you get to an eight-membered ring, you can have...0450

For example, cyclooctene can either be cis-cyclooctene where we draw our eight-membered ring and we put a double bond in there; now we see that those two alkyl groups are cis to each other.0456

Or it could be trans-cyclooctene; when we draw this, it gets a little more complicated because the molecule ends up being twisted because we put one alkyl group on the opposite side of the other.0475

But if the ring is large enough, then those two alkyl groups can still come around and be connected; so it is possible to have cis or trans.0488

Let's see, we have one, two, three, four, five, six, seven, eight carbons there; this is kind of passing behind the double bond; this is the 3D sketch.0495

Try building these models and you can get a feel for what cis and trans looks like.0505

But if it is a smaller ring, if we just have cyclopenetene or cyclohexene, we do not put the word cis as part of that name because it is impossible to have trans there.0509

Cis is assumed; and cis is going to be much more stable because it is a more stable ring that way.0517

If we happen to have more than one π bond, something we can look to for stabilizing the π bond is conjugation.0524

Conjugation is when we have a π bond; then a σ bond; and then another π bond; if our π bonds are separated by just one single bond, that is going to be a good relationship.0531

Because what happens... this is an example where we have a double bond, single bond, double bond; this is conjugated.0544

And this is not conjugated because separating these two π bonds, we have an sp3 hybridized carbon.0556

We take a look at the p orbitals here; we know that this π bond is a p orbital and a p orbital; and this π bond is a p orbital and a p orbital.0565

Look what happens when they are conjugated; we have p orbital, p orbital, p orbital, p orbital.0573

We end up getting delocalization of those π electrons over all four of these atoms; what we get is resonance stabilization.0578

We will be looking more at these conjugated systems down the road; but for now, we want to see it.0588

If we ever see it, we want to recognize that that is something is being stable; and that is more stable than having this π bond totally isolated from this π bond.0594

And there is no relationship between the p orbitals from one to the other; this is going to be more stable and the non-conjugated is going to be less stable.0603

That is something else we can look to stabilize a double bond if we can.0618

Finally, if we have something like this; this is an example of a bicyclic compound; it is a bridged compound; we have two rings in this molecule.0624

When you have a double bond in a bicyclic compound like this, we are going to look for the bridgehead carbons.0636

The bridgehead carbons are defined as those that are shared between multiple rings, where the two rings come together and there is a juncture; this is bridgehead carbon; this is a bridgehead carbon.0642

When you look at this molecule from the perspective of the bridgehead carbons, you see that these carbons are connected by three bridges.0652

Here is a one carbon bridge; here is a two carbon bridge; here is another two carbon bridge; we call these bridgehead carbons.0660

It turns out that having a double bond attached to one of those bridgehead carbons is very unstable; this molecule is not going to want to exist; it is going to be highly unstable.0666

It is okay to put a double bond somewhere else in the bicyclic compound; it is okay to have a bicyclic compound; over here would be okay because the double bond avoids the bridgehead position.0678

This is known as Bredt's rule; you might come across some examples where you are looking for where to put a double bond as a result of a reaction; we want to avoid bridgehead carbons.0689

This alkene stability can be measured; this is something that we can find some evidence for, these various rules that we are looking at.0701

By doing a reaction called a hydrogenation reaction and measuring the heat of that hydrogenation.0709

We are going to be talking about that in our next lecture when we look at some of the... that is one of the many reactions that we will be studying that alkenes can undergo.0713

How would we make an alkene?--if we want to put a carbon-carbon into a structure, there is really two major approaches that we would want to take.0723

One of them is going to be an E2 reaction on an alkyl halide; let's see an example of that.0731

How about if we wanted to transform this given starting material into the desired product; what a transform problem looks like is it means provide the necessary reagents to convert one to the other.0737

More than one step might be possible; it might not just be one reagent that you are putting in there; it might be multiple steps to convert one to the other.0750

If we compare our starting material to our product, we see that an elimination has taken place.0759

It must be an elimination because we've formed a double bond; we've lost the bromine--the leaving group; but we've also lost a hydrogen.0766

What we would need to consider is what mechanism do we want to employ in doing this elimination?--we have two choices; it could be either an E1 elimination or an E2 elimination.0780

There is some benefits to some; some might be more suitable; let's think about an E1 elimination; that was the mechanism that was the multistep elimination mechanism.0790

It started by loss of a leaving group to form a carbocation; carbocations are involved in the E1 mechanism; would this be a good substrate to form our carbocation?0803

We have our leaving group on a primary carbon; that would give us a primary carbocation; that is not a very good carbocation; that would be highly unstable.0814

I don't think an E1 is a good idea here because we have a primary leaving group; that would give a primary carbocation; that most certainly would rearrange.0826

I think we should avoid trying to do some kind of unimolecular elimination and count on a carbocation; instead we are going to do an E2.0841

E2 elimination was where we had some strong base attack in a single step mechanism; attack the β hydrogen, form the π bond, kick off the leaving group; that is our E2.0850

What we need here is we need a strong base; we need a strong base; if you had to think about a strong base, maybe sodium hydroxide comes to mind; that would definitely be a strong base.0861

But let's take a look at this starting material, this n-bromobutane or 1-bromobutane, and think about its reaction with sodium hydroxide.0882

Yes, it could do the E2; but is there another reaction that hydroxide can do?--remember that hydroxide can be both a base and a nucleophile; we have our competition here between Sn2 and E2.0892

Because we have a primary alkyl halide, what would be favored?--there is no steric hindrance; Sn2 is going to be favored.0906

Sodium hydroxide wouldn't work because that would give us the substitution product; how can we force the elimination then?--how can we suppress the substitution, the backside attack of the Sn2?0915

If there is some way we can increase the sterics of that backside attack, then that would help us; that would force the E2 be favored over the Sn2.0926

How about if we just used a different base?--what would be a bulkier base than sodium hydroxide?--how about t-butoxide as a base?0936

T-butoxide has a tert-butyl group; now it is very bulky; this is bulky; so E2 is major; even with a primary halide, the tert-butoxide favors the elimination.0945

All we need to do, in this case, our reagents... it can be done just in a single step... is we use t-butoxide.0960

Maybe we can throw in some heat if you want; that usually favors the elimination as well; but all we need in this case is a strong bulky base.0970

The E2 is a very good method for forming alkenes; very reliable single step; let's review some of the features of the E2.0978

Remember the stereochemistry of the E2; there was a relationship between our leaving group and our β hydrogen.0986

They had to be anti to one another; we call that anti elimination... anti elimination; we need to be able to achieve that stereochemistry in order to do the E2.0991

Our regiochemistry, this was governed by Zaitsev's rule; we wanted to get the most stable alkene ;in this case, we didn't form a very stable alkene; it is terminal; it is mono-substituted.1011

But because there was only one β hydrogen that was... one type of β hydrogen that is possible, this is the only E2 elimination product that is possible; this would be in fact our major product.1031

Zaitsev's rule comes into play when we have more than one β hydrogen from which to choose; the one we select is based on the one that would lead to the most stable alkene product.1043

Finally, how about the Sn2 versus E2?--because we are going to have that competition with our strong bases; they can also be nucleophiles.1056

As usual, as we increase our sterics, we know that is bad news for the backside attack for the Sn2; that is going to increase the proportion of the E2 elimination product.1065

We need to... if we want to increase our sterics, we need to have a nice repertoire of bulky bases from which to choose.1078

Of course, the t-butoxide is the one we are most familiar with; the t-butoxide; but there is some of other ones you can do as well.1087

There is some nice amine bases; amines have a nitrogen in them and they usually have some groups attached on that nitrogen.1096

For example, triethylamine, a nitrogen with three ethyl groups attached to it, like the tert-butyl group, very big and bulky; that is very good for doing eliminations.1105

Or diisopropylamine has a nitrogen with two isopropyl groups on it; look at all that steric hindrance, all that bulk; diisopropylamine is another example of a base that is good.1114

If you put that in there with an alkyl halide and warm it up, then you can have a good bet that E2 is going to be your major product there.1129

A second approach, besides doing the E2 elimination, is to start with an alcohol and do a dehydration reaction; here is an example of an alcohol.1140

In order to do a dehydration, we are going to react this either with H2SO4 and heat or maybe H3PO4; these are the ones we will probably see most often.1149

Some strong concentrated acid and heat--what happens is we get an elimination reaction to take place; we form an alkene product; we start with an alcohol and we form an alkene.1160

What did we just lose?--what has been eliminated in this elimination reaction?--we lost the OH, of course; but remember we also lost a β hydrogen; we lost an OH and an H.1175

It means we have a loss of H2O; that is why we call this reaction the dehydration reaction.1188

Because just like when you are out in the desert or you are running and you are dehydrated, you are low on water, dehydration means you are losing water; the other product in this reaction is water.1196

Let's think about the mechanism for this; how can this alcohol get converted to an alkene?--how can it lose water?1211

Clearly, we have very strongly acidic reaction conditions; what do you think our first step should be?--in a strong acid, we need to protonate something.1217

Let's look at our alcohol and think about where to protonate; we really only have one choice--on the oxygen; that in fact is going to be our first step of the reaction.1225

Let's just use HA to represent our strong acid; two arrows to do a proton transfer; and we can protonate the alcohol OH group.1235

Great idea for our first step because we are in strongly acidic reaction conditions; so protonate; what does that do for us though?--why would that be something that might move us toward our product?1251

Remember, once we protonate an alcohol, we turn that OH into a very good leaving group... very good leaving group; it is going to be... it would be water once it leaves, very stable molecule.1265

We now have a leaving group to do our elimination; now we should think, do you think it is going to be an E1 elimination mechanism?--an E2 elimination mechanism?1281

E2 means we have a strong base come in and attack the β hydrogen to kick out this leaving group; is that what happens?--do we have any strong bases in these reaction conditions?1288

No, of course not; we have very strong acid conditions; it can't be an E2 elimination; it can't be an E2 because there is no strong base.1299

Our only other choice is to be an E1; what does it mean to be an E1?--it means our leaving group just leaves on its own.1312

In acidic conditions, that is what we would get; our leaving group leaves on its own; this next step is loss of leaving group to give a carbocation intermediate.1320

This carbocation can go on to be a carbon-carbon double bond, to be an alkene; this how the E1 continues; how do we do that final step?1337

Remember we are losing water; we are losing the OH leaving group; but we are also losing a β hydrogen; what we do is we look to one of the hydrogens on the neighboring carbon.1349

I'm going to choose over here because that is going to give me a double bond that is more highly substituted, that is more stable; you could see that is the major product that was shown here.1359

I could just use A- as a good base; that was formed in that first step; but I could use A- to come back in here and deprotonate; carbocations can be deprotonated to form double bonds to form alkenes.1367

This last step we could describe as deprotonate or loss of the β hydrogen; we know that has to be part of an elimination; we want to put in that context.1385

We are going to protonate, lose our leaving group, and deprotonate; that is our E1 mechanism for dehydration.1398

What are some other things that we want to know about this dehydration mechanism?--because it is the E1 mechanism, it is going to give the most stable alkene; this will also follow Zaitsev's rule.1409

It involves a carbocation; we know carbocations can rearrange; if there is a possibility that we can have a hydride shift or an alkyl shift to go to a more stable position.1422

A more substituted carbocation, that can happen; that will happen; taking a look at our reaction conditions, remember that we are dealing with a very very strong acid.1433

We need that to make OH a good leaving group; we really have to have something like sulfuric acid as our catalyst in this reaction.1442

In my mechanism, I just used HA to represent sulfuric acid; that is a safe species to use in a mechanism to represent a strong acid.1451

But let's just remind ourselves what H2SO4 looks like; this is H2SO4.1460

After it protonates something, after it is used as an acid, we are left with A-; that is this species right here.1468

Why is sulfuric acid such a great acid?--why is it such a strong acid and so willing to donate its proton?--we could take a look at its conjugate base.1478

This is the conjugate base of sulfuric acid; do you think this is a pretty stable molecule or is this pretty reactive?--what do you think about it?1490

It has an O-; sometimes we consider that to be a strong base, but this is not a strong base; that is because this O- is resonance stabilized.1499

We can draw several resonance forms for this; I will just draw one here; this negative charge can also be delocalized on the third oxygen, the other oxygen down here.1510

That negative charge is equally delocalized over all three of these oxygens; which means it is very very stable and is resonance stabilized.1524

We have a very weak conjugate base; this is very stable, very unreactive, very weak; we would expect that for something that is the conjugate of a strong acid.1537

Because it is so stable, that makes it non-nucleophilic; in other words, there is going to be no Sn1 competition.1552

Normally up till now, every time we've seen a carbocation, we've used that carbocation; it had a nucleophile add to it and we've done a substitution reaction.1565

The only time we've seen elimination, we said that was just usually a side product for our substitutions; substitution is usually favored.1573

The dehydration reaction is the one example that deviates from that norm; it is simply because, in these reaction conditions, we have no nucleophile to add to the carbonyl, to the carbocation.1580

All we have is a strong acid and its weak conjugate base; once you form the carbocation, your only choice is to dehydrate, to eliminate and form the alkene double bond.1591

You can think of the A- like a spectator ion; you can use it as a mild base to deprotonate something that needs deprotonating.1603

But it is not going to be something that is going to be nucleophilic; that is not going to be participating in the reaction.1614

What I wanted to do is I wanted to compare a strong acid like H2SO4 with another strong acid like HCl.1621

What we just said about H2SO4 and heat, this looks like what kind of reaction conditions?--this looks like you are going to lose water; it is going to be dehydration.1629

Strong acid and heat on an alcohol, what would that product look like?--we have four carbons; we are going to lose water.1639

We would form the double bond between the middle two carbons here--that is more stable than being at the end; we can keep this trans relationship; that would be more stable.1649

Remember we could also form the cis-butene product; but that is going to be less stable; that would not be our major product.1658

Our major product is the most stable alkene we can have after rearrangements if they are necessary; in other words, we would expect E1 elimination to take place with H2SO4.1667

How does that differ when we react it with HCl?--HCl is unique because, not only is it a strong acid and a source of proton, it is also a source of Cl-.1679

It is a strong acid, plus it is a nucleophile, it is a source of a nucleophile; what happens when we react an alcohol with a haloacid like HCl?1691

We protonate to form a good leaving group; then the halogen replaces that leaving group; we get a substitution mechanism taking place either by the Sn1 mechanism or the Sn2 mechanism.1705

Both of those can happen with the halide; we can form a carbocation or the halide can do a backside attack.1717

But with an acid like HCl, we get substitution because, if there is a nucleophile present, that nucleophile will want to attack the carbocation.1724

With H2SO4 and heat, there is no nucleophile present; once we form the carbocation, our only choice is to eliminate and get the alkene product.1732

Let's try another example here; here we are given a reaction and we are asked to provide a mechanism; it looks like we have these two methyl groups here.1742

Remember our line drawing means these are methyl groups; it looks like those methyl groups used to be on the same carbon; now they are on different carbons.1757

I think we are going to have to do some kind of rearrangement in our mechanism to account for that.1766

How do you think we should get started?--I see that strong acid; I am going to protonate as my first step; that gives you HA to protonate.1771

Every step in this mechanism, the dehydration mechanism, is reversible; this oxygen now has just one lone pair; it has a positive charge; I protonate it.1783

After protonating, now I have a great leaving group that can leave; I show this bond breaking and leaving with water; this is where I just kicked out my water molecule; now I have a carbocation.1796

Let's put those CH3s back in again so we can see them a little more clearly; we are at the carbocation stage; now we can rearrange.1811

Remember a carbocation rearrangement is where we look over to one side or another and we try and find and steal some electrons, steal a bond that would result in a more stable carbocation.1825

What this carbocation sees is, if one of these methyl groups picked up and moved over to the next carbon over, we call that a methyl shift... a 1,2-methyl shift.1836

We now have one methyl up here and one methyl down here; where does that place our carbocation?--this carbon now has four bonds; it had only three before.1846

But this carbon just lost one of its bonds; the carbocation is now down here; why is that rearrangement favorable?1855

It is favorable because we have gone from a secondary carbocation to a tertiary carbocation which is more stable.1865

We always want to be on the lookout for any mechanism involving a carbocation; we want to be on the lookout for rearrangements; because if it can find a way to stabilize, it will.1876

How do we get to our alkene?--how do we do our last step here?--we need to form the double bond; now we need to deprotonate.1885

Where is the proton that we want to go for, we want to deprotonate?--it is not going to be at the carbon of the carbocation; it is going to be one of the adjacent carbons, one of the β positions.1893

Why did we not deprotonate in this direction?--because that would give us a double bond that is less highly substituted.1907

If we go for this hydrogen, that is going to give us the double bond between the two methyl groups; it is going to give us a tetra-substituted, which is the most stable we can have.1915

In this case, because it gave us the major product, we didn't have to make this decision; I just want to keep that in mind.1930

If you had to predict the product here, this is the product; this is why you would get the product you did.1936

We need to deprotonate; what can we use to deprotonate?--A- is the safest bet here; we just formed A- in the first step; you can also see that this is catalytic in acid.1941

For every protonation step, there is a deprotonation step; we grab that proton and use those electrons to forms a double bond.1950

We protonate, lose water, and then, in this case, we rearranged; then we deprotonated to form the double bond.1959

One more example, let's think about a transform; if I had an alcohol here; I am starting with an alcohol; I want to go to an alkene.1971

It is important to consider the functional groups in our starting material and our product to decide how we are going to convert one to the other.1983

We are back to our original problem; we want to form an alkene; the way we form an alkene is by eliminating to form the double bond.1991

You know our choices are E1, E2; those are the only elimination mechanisms we know so far; those are the only ways we know how to make alkenes so far; we will learn about some other down the road.2000

We have an alcohol; what if we took this and we treated it with H2SO4 and heat; we just learned that alcohols can be dehydrated; certainly this alcohol could be dehydrated.2010

Would that give this product that is shown as the major product?--let's think about that mechanism; we know this is going to be an E1 mechanism; it is carbocation conditions.2023

We are talking about a primary carbocation, highly unstable; but with immediate rearrangement, we can get to a secondary carbocation, maybe even a tertiary carbocation.2040

But most definitely, we would rearrange this carbocation; what do you think that major product would look like if we had to predict this?2050

I think we would end up forming the tri-substituted double bond, the internal double bond, as the major product.2060

Because we don't want that as our target molecule, as the thing we are trying to synthesize, then this would not be a good synthesis.2069

What is another way that we can put in that double bond?--we need to do an E2 elimination to form the double bond at the end here.2077

Why don't we treat this with t-butoxide?--we talked about t-butoxide as our bulky base... throw in a little heat... as our bulky base.2088

What would happen if you take an alcohol and you react it with t-butoxide?--would you expect the E2 elimination?--what is wrong with trying to do an E2 here?2098

You lose a β hydrogen and what?--a leaving group; we do not have a leaving group here with hydroxide.2107

This is no reaction because there is no leaving group; we wanted to try and do the E2; but that is not going to happen here.2113

How can we possibly do the E2 elimination?--what do we have to do?--we have to make the OH a good leaving group; then we can do the E2.2122

An ideal way to do that is to convert the alcohol to a tosylate; we can use some tosyl chloride in pyridine; that keeps the alcohol right where it is.2130

But turns the OH into an OTs which is now a great leaving group; now that you have this great leaving group, now you can treat it with t-butoxide and heat and do the E2 elimination.2145

If you don't want the tosylate, you can maybe use something like thionyl chloride, SoCl2, or PBr3 to convert it to a bromide or chloride.2163

Then we have a good leaving group and we can do an E2 elimination.2173

We want to keep in mind, in synthesizing alkenes, we need to know the mechanisms very well for the E1 and the E2 and decide which is appropriate in each condition, in each situation.2176

Next we will be talking about the reactions that we can do for alkenes once we have a carbon-carbon double bond in our structure.2188

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