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Dr. Laurie Starkey

Dr. Laurie Starkey

Alkane Structures

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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
1:00:45
Common Acids/Bases
1:00:46
Example: Determine the Direction of Equilibrium
1:04:51
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
1:03:11
Van Der Waals/ London Forces
1:03:12
Example: Van Der Waals/ London Forces
1:04:59
Water Solubility
1:08:32
Water Solubility
1:08:34
Example: Water Solubility
1:09:05
Example: Acetone
1:11:29
Isomerism
1:13:51
Definition of Isomers
1:13:53
Constitutional Isomers and Example
1:14:17
Stereoisomers and Example
1:15:34
Introduction to Functional Groups
1:17:06
Functional Groups: Example, Abbreviation, and Name
1:17:07
Introduction to Functional Groups
1:20:48
Functional Groups: Example, Abbreviation, and Name
1:20:49
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
1:02:14
Cyclohexane Chair Flips
1:04:06
Axial and Equatorial Groups
1:04:10
Example: Chair Flip on Methylcyclohexane
1:06:44
Cyclohexane Conformations Example
1:09:01
Chair Conformations of cis-1-t-butyl-4-methylcyclohexane
1:09:02
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
1:01:48
Drawing Stereoisomers
1:06:37
Draw All Stereoisomers of 2,3-dichlorobutane
1:06:38
Molecules with Two Chiral Centers
1:10:22
Draw All Stereoisomers of 2,3-dichlorobutane, cont.
1:10:23
Optical Activity
1:14:10
Chiral Molecules
1:14:11
Angle of Rotation
1:14:51
Achiral Species
1:16:46
Physical Properties of Stereoisomers
1:17:11
Enantiomers
1:17:12
Diastereomers
1:18:01
Example
1:18:26
Physical Properties of Stereoisomers
1:23:05
When Do Enantiomers Behave Differently?
1:23:06
Racemic Mixtures
1:28:18
Racemic Mixtures
1:28:21
Resolution
1:29:52
Unequal Mixtures of Enantiomers
1:32:54
Enantiomeric Excess (ee)
1:32:55
Unequal Mixture of Enantiomers
1:34:43
Unequal Mixture of Enantiomers
1:34:44
Example: Finding ee
1:36:38
Example: Percent of Composition
1:39:46
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
1:05:02
Aromatic Nomenclature and Examples
1:05:03
Aromatic Nomenclature, cont.
1:09:09
Ortho, Meta, and Para
1:09:10
Aromatic Nomenclature, cont.
1:13:27
Common Names for Simple Substituted Aromatic Compounds
1:13:28
Carboxylic Acid Nomenclature
1:16:35
Carboxylic Acid Nomenclature and Examples
1:16:36
Carboxylic Acid Derivatives
1:22:28
Carboxylic Acid Derivatives
1:22:42
General Structure
1:23:10
Acid Halide Nomenclature
1:24:48
Acid Halide Nomenclature and Examples
1:24:49
Anhydride Nomenclature
1:28:10
Anhydride Nomenclature and Examples
1:28:11
Ester Nomenclature
1:32:50
Ester Nomenclature
1:32:51
Carboxylate Salts
1:38:51
Amide Nomenclature
1:40:02
Amide Nomenclature and Examples
1:40:03
Nitrile Nomenclature
1:45:22
Nitrile Nomenclature and Examples
1:45:23
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?
1:00:40
Example 1: SN1 or SN2 Mechanisms
1:00:42
Example 2: SN1 or SN2 Mechanisms
1:03:00
Example 3: SN1 or SN2 Mechanisms
1:04:06
Example 4: SN1 or SN2 Mechanisms
1:06:17
SN1 Mechanism
1:09:12
Three Steps of SN1 Mechanism
1:09:13
SN1 Carbocation Rearrangements
1:14:50
Carbocation Rearrangements Example
1:14:51
SN1 Carbocation Rearrangements
1:20:46
Alkyl Groups Can Also Shift
1:20:48
Leaving Groups
1:24:26
Leaving Groups
1:24:27
Forward or Reverse Reaction Favored?
1:26:00
Leaving Groups
1:29:59
Making poor LG Better: Method 1
1:30:00
Leaving Groups
1:34:18
Making poor LG Better: Tosylate (Method 2)
1:34:19
Synthesis Problem
1:38:15
Example: Provide the Necessary Reagents
1:38:16
Nucleophilicity
1:41:10
What Makes a Good Nucleophile?
1:41:11
Nucleophilicity
1:44:45
Periodic Trends: Across Row
1:44:47
Periodic Trends: Down a Family
1:46:46
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
1:00:00
Example 2: Predict the Product
1:02:10
Example 3: Predict the Product
1:04:07
Predict the Product: SN2 vs. E2
1:06:06
Example 4: Predict the Product
1:06:07
Example 5: Predict the Product
1:07:29
Example 6: Predict the Product
1:07:51
Example 7: Predict the Product
1:09:18
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
1:00:08
Halohydrin: Regiochemistry
1:03:55
Halohydrin: Regiochemistry
1:03:56
Bromonium Ion Intermediate
1:04:26
Example
1:09:28
Example: Predict Major Product
1:09:29
Example Cont.
1:10:59
Example: Predict Major Product Cont.
1:11:00
Catalytic Hydrogenation of Alkenes
1:13:19
Features of Catalytic Hydrogenation
1:13:20
Catalytic Hydrogenation of Alkenes
1:14:48
Metal Surface
1:14:49
Heterogeneous Catalysts
1:15:29
Homogeneous Catalysts
1:16:08
Catalytic Hydrogenation of Alkenes
1:17:44
Hydrogenation & Pi Bond Stability
1:17:45
Energy Diagram
1:19:22
Catalytic Hydrogenation of Dienes
1:20:40
Hydrogenation & Pi Bond Stability
1:20:41
Energy Diagram
1:23:31
Example
1:24:14
Example: Predict Product
1:24:15
Oxidation of Alkenes
1:27:21
Redox Review
1:27:22
Epoxide
1:30:26
Diol (Glycol)
1:30:54
Ketone/ Aldehyde
1:31:13
Epoxidation
1:32:08
Epoxidation
1:32:09
General Mechanism
1:36:32
Alternate Epoxide Synthesis
1:37:38
Alternate Epoxide Synthesis
1:37:39
Dihydroxylation
1:41:10
Dihydroxylation
1:41:12
General Mechanism (Concerted Via Cycle Intermediate)
1:42:38
Ozonolysis
1:44:22
Ozonolysis: Introduction
1:44:23
Ozonolysis: Is It Good or Bad?
1:45:05
Ozonolysis Reaction
1:48:54
Examples
1:51:10
Example 1: Ozonolysis
1:51:11
Example
1:53:25
Radical Addition to Alkenes
1:55:05
Recall: Free-Radical Halogenation
1:55:15
Radical Mechanism
1:55:45
Propagation Steps
1:58:01
Atom Abstraction
1:58:30
Addition to Alkene
1:59:11
Radical Addition to Alkenes
1:59:54
Markovnivok (Electrophilic Addition) & anti-Mark. (Radical Addition)
1:59:55
Mechanism
2:01:03
Alkene Polymerization
2:05:35
Example: Alkene Polymerization
2:05:36
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
1:01:07
Example 3: Transform
1:06:22
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
1:01:03
Transformation
1:01:04
Regiochemistry of Epoxide Ring Openings
1:05:29
Regiochemistry of Epoxide Ring Openings in Base
1:05:30
Regiochemistry of Epoxide Ring Openings in Acid
1:07:34
Example
1:10:26
Example 1: Epoxide Ring Openings in Base
1:10:27
Example 2: Epoxide Ring Openings in Acid
1:12:50
Reactions of Epoxides with Grignard and Hydride
1:15:35
Reactions of Epoxides with Grignard and Hydride
1:15:36
Example
1:21:47
Example: Ethers
1:21:50
Example
1:27:01
Example: Synthesize
1:27:02
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
1:01:43
Predict
1:01:44
Mechanism
1:03:08
Mechanism for Acetal Formation
1:04:10
Mechanism for Acetal Formation
1:04:11
What is a CTI?
1:15:04
Tetrahedral Intermediate
1:15:05
Charged Tetrahedral Intermediate
1:15:45
CTI: Acid-cat
1:16:10
CTI: Base-cat
1:17:01
Acetals & Cyclic Acetals
1:17:49
Overall
1:17:50
Cyclic Acetals
1:18:46
Hydrolysis of Acetals: Regenerates Carbonyl
1:20:01
Hydrolysis of Acetals: Regenerates Carbonyl
1:20:02
Mechanism
1:22:08
Reaction with Nitrogen Nu:
1:30:11
Reaction with Nitrogen Nu:
1:30:12
Example
1:32:18
Mechanism of Imine Formation
1:33:24
Mechanism of Imine Formation
1:33:25
Oxidation of Aldehydes
1:38:12
Oxidation of Aldehydes 1
1:38:13
Oxidation of Aldehydes 2
1:39:52
Oxidation of Aldehydes 3
1:40:10
Reductions of Ketones and Aldehydes
1:40:54
Reductions of Ketones and Aldehydes
1:40:55
Hydride/ Workup
1:41:22
Raney Nickel
1:42:07
Reductions of Ketones and Aldehydes
1:43:24
Clemmensen Reduction & Wolff-Kishner Reduction
1:43:40
Acetals as Protective Groups
1:46:50
Acetals as Protective Groups
1:46:51
Example
1:50:39
Example: Consider the Following Synthesis
1:50:40
Protective Groups
1:54:47
Protective Groups
1:54:48
Example
1:59:02
Example: Transform
1:59:03
Example: Another Route
2:04:54
Example: Transform
2:08:49
Example
2:08:50
Transform
2:08:51
Example
2:11:05
Transform
2:11:06
Example
2:13:45
Transform
2:13:46
Example
2:15:43
Provide the Missing Starting Material
2:15:44
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
1:03:06
Ester Hydrolysis Requires Acide or Base
1:03:07
Nitrile Hydrolysis
1:05:22
Nitrile Hydrolysis
1:05:23
Nitrile Hydrolysis Mechanism
1:06:53
Nitrile Hydrolysis Mechanism
1:06:54
Use of Nitriles in Synthesis
1:12:39
Example: Nitirles in Synthesis
1:12:40
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
1:01:41
A) Hydride Nu: Review
1:01:42
A) Hydride Nu: Sodium Borohydride + Ester
1:02:43
Reactions of Carboxylic Acid Derivatives with Nucleophiles
1:03:57
Lithium Aluminum Hydride (LAH)
1:03:58
Mechanism
1:04:29
Summary of Hydride Reductions
1:07:09
Summary of Hydride Reductions 1
1:07:10
Summary of Hydride Reductions 2
1:07:36
Hydride Reduction of Amides
1:08:12
Hydride Reduction of Amides Mechanism
1:08:13
Reaction of Carboxylic Acid Derivatives with Organometallics
1:12:04
Review 1
1:12:05
Review 2
1:12:50
Reaction of Carboxylic Acid Derivatives with Organometallics
1:14:22
Example: Lactone
1:14:23
Special Hydride Nu: Reagents
1:16:34
Diisobutylaluminum Hydride
1:16:35
Example
1:17:25
Other Special Hydride
1:18:41
Addition of Organocuprates to Acid Chlorides
1:19:07
Addition of Organocuprates to Acid Chlorides
1:19:08
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
1:00:55
Crossed/Mixed Aldol & Compound with α H's
1:00:56
Ketone vs. Aldehyde
1:02:30
Crossed/Mixed Aldol & Compound with α H's Continue
1:03:10
Crossed/Mixed Aldol
1:05:21
Mixed Aldol: control Using LDA
1:05:22
Crossed/Mixed Aldol Retrosynthesis
1:08:53
Example: Predic Aldol Starting Material (Aldol Retrosyntheiss)
1:08:54
Claisen Condensation
1:12:54
Claisen Condensation (Aldol on Esters)
1:12:55
Claisen Condensation
1:19:52
Example 1: Claisen Condensation
1:19:53
Claisen Condensation
1:22:48
Example 2: Claisen Condensation
1:22:49
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
1:02:24
Electrophilic Aromatic Substitution: Friedel-Crafts Alkylation
1:02:25
Example & Mechanism
1:03:37
Friedel-Crafts Alkylation Drawbacks
1:05:48
A) Can Over-React (Dialkylation)
1:05:49
Friedel-Crafts Alkylation Drawbacks
1:08:21
B) Carbocation Can Rearrange
1:08:22
Mechanism
1:09:33
Friedel-Crafts Alkylation Drawbacks
1:13:35
Want n-Propyl? Use Friedel-Crafts Acylation
1:13:36
Reducing Agents
1:16:45
Synthesis with Electrophilic Aromatic Substitution
1:18:45
Example: Transform
1:18:46
Synthesis with Electrophilic Aromatic Substitution
1:20:59
Example: Transform
1:21:00
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
1:01:27
Explain Why No Diels-Alder Reaction Takes Place in This Case
1:01:28
Diels-Alder Reaction
1:03:09
Example: Predict
1:03:10
Diels-Alder Reaction: Synthesis Problem
1:05:39
Diels-Alder Reaction: Synthesis Problem
1:05:40
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
1:07:40
Pericyclic Reaction Example II
1:07:41
Pericyclic Reaction Example III: Vitamin D - The Sunshine Vitamin
1:14:22
Pericyclic Reaction Example III: Vitamin D - The Sunshine Vitamin
1:14:23
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
1:00:28
Isoelectric Point (pI), cont.
1:02:54
Example: What is the Net Charge of This Tetrapeptide at pH 6.0?
1:02:55
Nucleic Acids: Ribonucleosides
1:10:32
Nucleic Acids: Ribonucleosides
1:10:33
Nucleic Acids: Ribonucleotides
1:11:48
Ribonucleotides: 5' Phosphorylated Ribonucleosides
1:11:49
Ribonucleic Acid (RNA) Structure
1:12:35
Ribonucleic Acid (RNA) Structure
1:12:36
Nucleic Acids: Deoxyribonucleosides
1:14:08
Nucleic Acids: Deoxyribonucleosides
1:14:09
Deoxythymidine (T)
1:14:36
Nucleic Acids: Base-Pairing
1:15:17
Nucleic Acids: Base-Pairing
1:15:18
Double-Stranded Structure of DNA
1:18:16
Double-Stranded Structure of DNA
1:18:17
Model of DNA
1:19:40
Model of DNA
1:19:41
Space-Filling Model of DNA
1:20:46
Space-Filling Model of DNA
1:20:47
Function of RNA and DNA
1:23:06
DNA & Transcription
1:23:07
RNA & Translation
1:24:22
Genetic Code
1:25:09
Genetic Code
1:25:10
Lipids/Fats/Triglycerides
1:27:10
Structure of Glycerol
1:27:43
Saturated & Unsaturated Fatty Acids
1:27:51
Triglyceride
1:28:43
Unsaturated Fats: Lower Melting Points (Liquids/Oils)
1:29:15
Saturated Fat
1:29:16
Unsaturated Fat
1:30:10
Partial Hydrogenation
1:32:05
Saponification of Fats
1:35:11
Saponification of Fats
1:35:12
History of Soap
1:36:50
Carboxylate Salts form Micelles in Water
1:41:02
Carboxylate Salts form Micelles in Water
1:41:03
Cleaning Power of Micelles
1:42:21
Cleaning Power of Micelles
1:42:22
3-D Image of a Micelle
1:42:58
3-D Image of a Micelle
1:42:59
Synthesis of Biodiesel
1:44:04
Synthesis of Biodiesel
1:44:05
Phosphoglycerides
1:47:54
Phosphoglycerides
1:47:55
Cell Membranes Contain Lipid Bilayers
1:48:41
Cell Membranes Contain Lipid Bilayers
1:48:42
Bilayer Acts as Barrier to Movement In/Out of Cell
1:50:24
Bilayer Acts as Barrier to Movement In/Out of Cell
1:50:25
Organic Chemistry Meets Biology… Biochemistry!
1:51:12
Organic Chemistry Meets Biology… Biochemistry!
1:51:13
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
1:02:05
Alkyne to Cis Alkene
1:02:06
Alkyne to Trans Alkene
1:02:56
Synthesis of Alkenes by Wittig Reaction
1:03:46
Synthesis of Alkenes by Wittig Reaction
1:03:47
Retrosynthesis of an Alkene
1:05:35
Example: Synthesis of an Alkene
1:06:57
Example: Synthesis of an Alkene
1:06:58
Making a Wittig Reagent
1:10:31
Synthesis of Alkynes
1:13:09
Synthesis of Alkynes
1:13:10
Synthesis of Alkynes by Elimination (FGI)
1:13:42
First Step: Bromination of Alkene
1:13:43
Second Step: KOH Heat
1:14:22
Synthesis of Alkynes by Alkylation
1:15:02
Synthesis of Alkynes by Alkylation
1:15:03
Retrosynthesis of an Alkyne
1:16:18
Example: Synthesis of an Alkyne
1:17:40
Example: Synthesis of an Alkyne
1:17:41
Synthesis of Alkanes
1:20:52
Synthesis of Alkanes
1:20:53
Synthesis of Aldehydes & Ketones
1:21:38
Oxidation of Alcohol Using PCC or Swern
1:21:39
Oxidation of Alkene Using 1) O₃, 2)Zn
1:22:42
Reduction of Acid Chloride & Nitrile Using DiBAL-H
1:23:25
Hydration of Alkynes
1:24:55
Synthesis of Ketones by Acyl Substitution
1:26:12
Reaction with R'₂CuLi
1:26:13
Reaction with R'MgBr
1:27:13
Synthesis of Aldehydes & Ketones by α-Alkylation
1:28:00
Synthesis of Aldehydes & Ketones by α-Alkylation
1:28:01
Retrosynthesis of a Ketone
1:30:10
Acetoacetate Ester Synthesis of Ketones
1:31:05
Acetoacetate Ester Synthesis of Ketones: Step 1
1:31:06
Acetoacetate Ester Synthesis of Ketones: Step 2
1:32:13
Acetoacetate Ester Synthesis of Ketones: Step 3
1:32:50
Example: Synthesis of a Ketone
1:34:11
Example: Synthesis of a Ketone
1:34:12
Synthesis of Carboxylic Acids
1:37:15
Synthesis of Carboxylic Acids
1:37:16
Example: Synthesis of a Carboxylic Acid
1:37:59
Example: Synthesis of a Carboxylic Acid (Option 1)
1:38:00
Example: Synthesis of a Carboxylic Acid (Option 2)
1:40:51
Malonic Ester Synthesis of Carboxylic Acid
1:42:34
Malonic Ester Synthesis of Carboxylic Acid: Step 1
1:42:35
Malonic Ester Synthesis of Carboxylic Acid: Step 2
1:43:36
Malonic Ester Synthesis of Carboxylic Acid: Step 3
1:44:01
Example: Synthesis of a Carboxylic Acid
1:44:53
Example: Synthesis of a Carboxylic Acid
1:44:54
Synthesis of Carboxylic Acid Derivatives
1:48:05
Synthesis of Carboxylic Acid Derivatives
1:48:06
Alternate Ester Synthesis
1:48:58
Using Fischer Esterification
1:48:59
Using SN2 Reaction
1:50:18
Using Diazomethane
1:50:56
Using 1) LDA, 2) R'-X
1:52:15
Practice: Synthesis of an Alkyl Chloride
1:53:11
Practice: Synthesis of an Alkyl Chloride
1:53:12
Patterns of Functional Groups in Target Molecules
1:59:53
Recall: Aldol Reaction
1:59:54
β-hydroxy Ketone Target Molecule
2:01:12
α,β-unsaturated Ketone Target Molecule
2:02:20
Patterns of Functional Groups in Target Molecules
2:03:15
Recall: Michael Reaction
2:03:16
Retrosynthesis: 1,5-dicarbonyl Target Molecule
2:04:07
Patterns of Functional Groups in Target Molecules
2:06:38
Recall: Claisen Condensation
2:06:39
Retrosynthesis: β-ketoester Target Molecule
2:07:30
2-Group Target Molecule Summary
2:09:03
2-Group Target Molecule Summary
2:09:04
Example: Synthesis of Epoxy Ketone
2:11:19
Synthesize the Following Target Molecule from Cyclohexanone: Part 1 - Retrosynthesis
2:11:20
Synthesize the Following Target Molecule from Cyclohexanone: Part 2 - Synthesis
2:14:10
Example: Synthesis of a Diketone
2:16:57
Synthesis of a Diketone: Step 1 - Retrosynthesis
2:16:58
Synthesis of a Diketone: Step 2 - Synthesis
2:18:51
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
1:00:52
Example 8
1:02:20
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'
1:01:24
Understanding Splitting Patterns: The 'n+1 Rule'
1:01:25
Explanation of n+1 Rule
1:02:42
Explanation of n+1 Rule: One Neighbor
1:02:43
Explanation of n+1 Rule: Two Neighbors
1:06:23
Summary of Splitting Patterns
1:06:24
Summary of Splitting Patterns
1:10:45
Predicting ¹H NMR Spectra
1:10:46
Example 1: Predicting ¹H NMR Spectra
1:13:30
Example 2: Predicting ¹H NMR Spectra
1:19:07
Example 3: Predicting ¹H NMR Spectra
1:23:50
Example 4: Predicting ¹H NMR Spectra
1:29:27
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)
1:02:40
Allylic (4-bond) and W-coupling (4-bond) (Rigid Structures Only)
1:04:05
¹H NMR Advanced Splitting Patterns
1:05:39
Example 1: ¹H NMR Advanced Splitting Patterns
1:05:40
Example 2: ¹H NMR Advanced Splitting Patterns
1:10:01
Example 3: ¹H NMR Advanced Splitting Patterns
1:13:45
¹H NMR Practice
1:22:53
¹H NMR Practice 5: C₁₁H₁₇N
1:22:54
¹H NMR Practice 6: C₉H₁₀O
1:34:04
¹³C NMR Spectroscopy
1:44:49
¹³C NMR Spectroscopy
1:44:50
¹³C NMR Chemical Shifts
1:47:24
¹³C NMR Chemical Shifts Part 1
1:47:25
¹³C NMR Chemical Shifts Part 2
1:48:59
¹³C NMR Practice
1:50:16
¹³C NMR Practice 1
1:50:17
¹³C NMR Practice 2
1:58:30
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
1:01:29
McLafferty Rearrangement
1:01:30
Mass Spectra of Esters
1:04:15
Mass Spectra of Esters
1:01:16
Mass Spectrometry Discussion I
1:05:01
For the Given Molecule (M=58), Do You Expect the More Abundant Peak to Be m/z 15 or m/z 43?
1:05:02
Mass Spectrometry Discussion II
1:08:13
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?
1:08:14
Mass Spectrometry Discussion III
1:11:42
Explain Why the Mass Spectra of Methyl Ketones Typically have a Peak at m/z 43
1:11:43
Mass Spectrometry Discussion IV
1:14:46
In the Mass Spectrum of the Given Molecule (M=88), Account for the Peaks at m/z 45 and m/z 57
1:14:47
Mass Spectrometry Discussion V
1:18:25
How Could You Use Mass Spectrometry to Distinguish Between the Following Two Compounds (M=73)?
1:18:26
Mass Spectrometry Discussion VI
1:22:45
What Would be the m/z Ratio for the Fragment for the Fragment Resulting from a McLafferty Rearrangement for the Following Molecule (M=114)?
1:22:46
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 (74)

1 answer

Last reply by: Professor Starkey
Tue Nov 13, 2018 12:51 PM

Post by Angela Mercado on October 17 at 01:38:20 PM

Hi professor,

I was wondering @14.42 why we are not labeling the compound the opposite way? I thought alkyl halides take priority over regular alkyl substituents when numbering the longest carbon chain? Would the compound not be 2,3-dichloro-7,7-dimethyloctane?

1 answer

Last reply by: Professor Starkey
Sat Jan 13, 2018 6:41 PM

Post by Jade Huynh on November 22, 2017

Hi Professor Starkey! I was wondering if we were to have a nitrogen and/or phosphorus in our molecular formula, would we just subtract one hydrogen per nitrogen and/or phosphorus from the alkane formula?

For example, if we were asked to find the DU of the the following formula C9H11OP and I wanted to compare it to the alkane formula, would the alkane formula be would C9H19?

1 answer

Last reply by: Professor Starkey
Tue Oct 10, 2017 1:32 AM

Post by Maryam Fayyazi on October 5, 2017

How to distinguish  between cis,trans isomers and  eclipse,staggerd?

1 answer

Last reply by: Professor Starkey
Fri Feb 3, 2017 9:57 PM

Post by FALIKOU DUKULY on January 16, 2017

hi Dr.Starkey, how can you have CH3(CH3)4CH3 as pentane? isn't is supposed to be CH3(CH2)4CH3? if not how does CH3(CH3)4CH3 bond to each other?

2 answers

Last reply by: omeed tarzi
Thu Oct 6, 2016 2:01 PM

Post by omeed tarzi on October 6, 2016

is numbering right for 6,7-dichloro-2,2-dimthyl ......
?????? why we not start numbering from cl ????? plz explain

1 answer

Last reply by: Professor Starkey
Mon Mar 16, 2015 11:33 PM

Post by Saadman Elman on March 15, 2015

Hi, Professor, Starkey. As usual great lecture. At 68:30 min When you were explaining which side of cyclohexane is more stable. You said the one in the left is less stable and the reason is Ch3 in the axial side has a steric of 1-4 Diaxial interaction. I think you meant to say 1-3 diaxial interaction and Not 1-4 Diaxial interaction. Am i correct? Or i am having misunderstanding. I think that's what my professor said.

1 answer

Last reply by: Professor Starkey
Sat Feb 21, 2015 11:22 PM

Post by amanda Cormier on February 19, 2015

How did you get to be so awesome? You're saving my life in Ochem!

1 answer

Last reply by: Professor Starkey
Fri Dec 5, 2014 1:19 AM

Post by Camille Fraser on December 3, 2014

In the very last question in minuet 69 of Cyclohexane  Conformation example do you first always have to draw the original structure and then put it in the chair? Also is that a methyl group attached to the t-butyl in the cyclohexane model...at the base?

1 answer

Last reply by: Professor Starkey
Fri Dec 5, 2014 1:22 AM

Post by Camille Fraser on December 3, 2014

Please when writing on the board closer to the bottom make sure WE can all see the problem. When explaining the Alkanes at the end I could not see the other Chloro group in the octane molecule and the other subs were not clear closer to the front end of the structure.

1 answer

Last reply by: Professor Starkey
Thu Aug 7, 2014 8:47 PM

Post by David Gonzalez on August 5, 2014

I know this is slightly off topic, but is a fatty acid considered an alkane (since it's made up of hydrocarbons)? Thank you professor Starkey.

1 answer

Last reply by: Professor Starkey
Sat Jul 19, 2014 10:23 PM

Post by David Gonzalez on July 17, 2014

What if there are two groups coming from the same carbon? How would you name that? Thanks Professor Starkey.

1 answer

Last reply by: Professor Starkey
Mon Jun 23, 2014 1:22 PM

Post by Neil Choudhry on June 22, 2014

For the degrees of unsaturation, what do you do if there are Nitrogen atoms? For example, C3H9N

1 answer

Last reply by: Professor Starkey
Sat May 10, 2014 12:05 AM

Post by somia abdelgawad on May 7, 2014

on 69 minute is 1,4 diaxial or 1, 3 diaxial interaction.

2 answers

Last reply by: brandon oneal
Sat Nov 23, 2013 12:36 PM

Post by brandon oneal on November 15, 2013

Will you have lectures for organic chemistry II?

1 answer

Last reply by: Professor Starkey
Sun Sep 29, 2013 1:55 PM

Post by Shawn Ng on September 28, 2013

Hi Dr. Starkey,

At 10.30, shouldn't n-butyl be R-CH2CH2CH2CH3 instead of R-CH2CH2CH3CH3?

1 answer

Last reply by: Professor Starkey
Sun Sep 15, 2013 1:45 PM

Post by Kingsley Lunga on September 14, 2013

I am feeling extremely disappointed right now, I just purchased a subscription yester and I am not able to watch a video consistently for 10 minutes without it freezing on me. Also, it wont let me go to a specific topic that i'd like to watch, if you click on any sub topic, it takes you to the Main topic and this is very frustration, plus it wont even let you fast forward....please can someone offer some suggestions for me, all my excitement about educator.com is doing down.

1 answer

Last reply by: Professor Starkey
Sun Sep 15, 2013 3:23 PM

Post by Kingsley Lunga on September 14, 2013

I am using high speed internet with a very good laptop but the lecture keeps freezing after every 5 minutes, is anyone experiencing this?

1 answer

Last reply by: Professor Starkey
Tue Sep 10, 2013 4:34 PM

Post by Fadel Hanoun on September 9, 2013

Thank you for breaking this complicated subject so well. Is it possible to get a copy of the lecture slides in higher resolution?

1 answer

Last reply by: Professor Starkey
Mon Jul 22, 2013 12:00 AM

Post by Fadel Hanoun on July 21, 2013

I am wondering how come Energy of B > C when the methyl groups are closer apart in C than in B.

1 answer

Last reply by: Professor Starkey
Thu Jul 11, 2013 3:40 PM

Post by noelle edejer on July 11, 2013

i cant see the bottom and the writing is not clear

1 answer

Last reply by: Nawaphan Jedjomnongkit
Mon Apr 29, 2013 3:11 AM

Post by Nawaphan Jedjomnongkit on April 29, 2013

from second slide on nomenclature of alkanes Why CH3CH2- is propyl not ethyl?

1 answer

Last reply by: Professor Starkey
Fri Mar 1, 2013 11:22 PM

Post by James Bond on March 1, 2013

On 8:12, what if there were 2 methyl groups attached at carbon 2. What would the name be then?

1 answer

Last reply by: Professor Starkey
Tue Feb 12, 2013 10:45 AM

Post by SINA AZADI on February 11, 2013

Thank you so much Dr. Starkey. You are the most helpful teacher I ever had in my chemistry courses. Barely Understood some concepts.

1 answer

Last reply by: Professor Starkey
Mon Oct 15, 2012 9:55 PM

Post by noor almakabi on October 14, 2012

Hi Starkey,

Can we say for 2-methylpropane that it has 4 eclipsed conformation at 4 different degrees (0⁰,360⁰,120⁰,240⁰) and 2 staggered conformation at 3 different degrees (60⁰,300⁰,180⁰)?

1 answer

Last reply by: Professor Starkey
Fri Oct 12, 2012 8:36 PM

Post by José Menéndez on October 12, 2012

hey, how do I know it's a 60 degrees rotation or 120 etc?

1 answer

Last reply by: José Menéndez
Fri Oct 12, 2012 1:00 PM

Post by Paula Hoggard on October 11, 2012

How do I get to newman right away? I want to skip the beginning and I can't click on what I want!

1 answer

Last reply by: Professor Starkey
Tue Oct 2, 2012 11:24 PM

Post by Ty Smith on October 1, 2012

You are an excellent teacher. Thank you for doing these.

1 answer

Last reply by: Professor Starkey
Wed Jan 4, 2012 10:53 PM

Post by Lilian Comparini on January 2, 2012

You are amazing, I finally get concepts that until you explained them seemed complicated. thank you! I am more confident about taking my DAT thanks to you.

1 answer

Last reply by: Professor Starkey
Thu Oct 20, 2011 11:45 PM

Post by SHADLIN MOTARASSED on October 15, 2011

Is Example 3 when discussing DU Benzene? I think it is Hexene???

1 answer

Last reply by: Professor Starkey
Sun Sep 25, 2011 7:28 PM

Post by valerie phan on September 18, 2011

I really like this video and the tools you used! I wish there are more professors like you. Thank you so much. I just wanted to say that because you made ochem seem less scary compare to the rumors. =[

1 answer

Last reply by: Professor Starkey
Sat Jul 30, 2011 12:07 AM

Post by Daniela Valencia on July 2, 2011

Dr. Starkey
I love how you teach, your videos have helped me a lot with my studying, I will be taking my PCAT test next month. Thank you!!! You're a great teacher!

1 answer

Last reply by: Professor Starkey
Sat Jul 30, 2011 12:07 AM

Post by chen yakar on June 29, 2011

This is great!!

1 answer

Last reply by: Professor Starkey
Sat Jul 30, 2011 12:08 AM

Post by Priscilla Seabourn on June 27, 2011

Dr. Starkey, you have been extremely helpful. I am taking my MCAT soon, and you have helped tremendously! Thank you.

0 answers

Post by Billy Jay on April 12, 2011

Awesome. Can't wait to see those. Any idea if they'll be uploaded before June? If you're unsure, it's fine. I was just curious because my MCAT is scheduled for that date. Thank you.

3 answers

Last reply by: Professor Starkey
Mon Jul 8, 2013 11:13 PM

Post by Billy Jabbar on March 15, 2011


Hi Dr. Starkey,

For the chair conformation of cyclohexane - you mention that there are "1,4-diaxial interactions." I'm thinking you meant "1,3-diaxial interactions" instead, am I right? :)

Also, well done on the videos. They've been extremely helpful so far. I enjoy your enthusiasm (it's very contagious) and it's made this learning experience very enjoyable :)

One more question though: I noticed a few topics are left out such as Spectroscopy. Any chance those will be included in the future?

Thank you.

0 answers

Post by ochemstarkey on February 4, 2011

At 13:48, an extra example was drawn on screen, but the bottom constituent was cut off by the navigation bar. Would be nice if the navigation bar could be hidden with a button for such occasions. Another idea would be to just have the navigation bar not in the window at all, that way it would never even need to be hidden.

Alkane Structures

Give the IUPAC name for the following compound:
(CH3CH2)3CCH(CH3)CH2CH2CH3
  • Longest chain has 7 carbons = heptane
3,3-diethyl-4-methylheptane
Convert the structure to a Newman projection around the marked bond:
Draw the structure of the given compound:
3-ethyl-1,1-dimethylcyclohexane
Draw a second chair conformation for the following compound:
Rank these alkanes in order of increasing boiling point:
CH3CH2CH2CH2CH3, CH3CH2CH2CH2CH2CH2CH3, CH3CH2CH3
  • CH3CH2CH2CH2CH3 = 5C's
    CH3CH2CH2CH2CH2CH2CH3= 7C's
    CH3CH2CH3 = 3C's
  • Increasing number of C's or increasing surface area = increasing boiling point
CH3CH2CH3< CH3CH2CH2CH2CH3< CH3CH2CH2CH2CH2CH2CH3
Draw 3 constitutional isomers for the following compound: C7H16

*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

Alkane Structures

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

Transcription: Alkane Structures

Welcome back to Educator.0000

Next we are going to talk about alkane structures.0002

How do we name alkanes (that would be their nomenclature), what kind of physical properties do they have, what kind of shapes to they have?--that sort of thing.0005

We'll start with the nomenclature of alkanes.0013

Unfortunately, this is the one part of organic chemistry where you can't avoid doing some memorization.0016

Because just like we have to memorize the alphabet in order to learn how to spell and communicate with the written language, we need to know the names of organic molecules if we are to communicate about them.0022

I've shown here the first ten alkanes--C1 through C10.0035

These ten names--you will most definitely need to commit to memory; and so this is maybe a good time for some flashcards and some practice.0043

But of course the more you practice with these, these are going to become second nature to you much like the alphabet is to you.0052

The very simplest alkane with one carbon is called methane.0059

Two carbons is ethane; propane; butane.0062

Pentane is the five carbon just like a pentagon has five sides so that prefix isn't too hard to know.0066

Same with hexane just like a hexagon; hexane has six carbons.0073

Heptane has seven; octane has eight carbons just like the octopus or the octagon has eight sides or eight legs.0077

Nonane is nine; and decane is ten; again, that is a pretty easy one to remember since a decade is ten years.0085

Out of these ten that you... at least these ten you will need to know.0091

Some of them are quite easy and others you will quickly become familiar with as you start working with them.0096

Now what we are going to find when we go to name an alkane is we are going to first identify a parent carbon chain.0104

We are going to give that parent carbon chain one of these names--methane, propane, decane, and so on.0111

Attached to that carbon chain are going to be additional groups; we can call those substituents because they are substituted onto the carbon chain.0117

If one of those substituents is another carbon chain, we are going to name that substituent with the same sort of nomenclature.0124

But we are going to replace... instead of having an -ANE ending like we do for our parent chain, we are going to have a ?YL ending.0135

A one-carbon carbon group is called a methyl group.0144

Two carbons... I'm sorry, three carbons is called a propyl group.0150

Two carbons is called an ethyl; and we could have hexyl and octyl and so on.0155

It is also common to have halogens attached to our alkaness; so let's talk about that nomenclature as well.0161

We are going to add an -O... use an -O suffix for these groups.0168

So a fluoro, chloro, bromo, iodo is what we call it when it's a halogen attached.0172

It is also quite common to find a benzene ring attached to a parent chain.0176

Whenever we encounter that we are going to call that a phenyl group; so that is good to know as well.0180

The rules we are going to follow in doing our nomenclature is--the very first thing we are going to do is to inspect the structure and identify the longest carbon chain.0187

If we have more than one choice, we are going to identify the one with the maximum # of substituents.0196

And we are going to name that parent, again, using one of these names shown--propane, butane, and so on.0202

The next thing we need to do is we need to number the carbon chain.0209

And we are going to... we have to number from one end or the other.0213

And we are going to choose the end that is closest to the first substituent.0217

Then we are going to name and number the substituents that are attached.0222

We are going to see how you can use prefixes like di- and tri- and tetra- and so on in just a moment.0225

Finally, we are going to alphabetize all of our substituent names and list them out in front to come up with a complete IUPAC name.0230

IUPAC stands for the International Union of Pure and Applied Chemists; this is the committee that has developed these names.0238

The beauty of nomenclature for organic chemistry (although it might not be the most exciting subject in the world) is that all around the world all chemists use this same nomenclature rules.0248

Whether you are English-speaking or not, when you see this molecule and follow these same systematic rules, every person around the world should come up with the same name for that molecule.0262

That is what makes it a very important thing to know.0274

For example, we can look at this very simple example.0279

We have a three carbon chain; so a three carbon chain is going to be called a propane.0283

But it is not just propane, right?--because we have this chlorine attached to it; and we need to figure out where it is attached.0291

The way we are going to do that is--we are going to number the carbon chain.0298

In this case, it doesn't matter which end we start numbering from; we will get the same result--one, two, three.0301

We see that the chlorine is on the second carbon; so we are going to call this a 2-chloropropane.0306

And this all becomes all one word; there is no space here; we are going to put a dash in between numbers and letters; so this molecule is called 2-chloropropane.0315

How about the next one?; our first step is to find the longest carbon chain.0325

I see a one, two, three, four-carbon chain here; so this is going be a butane derivative.0331

Then we need to number the chain; if we numbered from this end--one, two, three; our substituent would be on the third carbon.0345

If we numbered from this end--one, two; our substituent would be on the second carbon.0352

We are going to number it in such a way to give the substituents the lowest possible numbers.0357

What do we have attached to... sometimes it is really useful to put a box around or a circle around your parent chains so you remember which carbons you have accounted for just by naming the parent.0365

We now have an additional carbon off of carbon 2.0377

We are not going to call that a methane group--there is no such thing; we call it a methyl group; we use the ?yl.0381

So we have a 2-methyl... butane is the name of the structure; 2-methylbutane.0386

The next one is a little more challenging because we have to search for our longest carbon chain.0396

If we look straight across--one, two, three, four; we would find a four-carbon chain.0400

But if we follow a different path and go up here, we see that we can come up with a longer carbon chain.0405

Remember a molecule can be drawn in any way so you want to look very closely to find the longest continuous carbon chain.0413

As long as you are still connecting to another carbon, you don't stop till you hit an end--a carbon that has no other carbons attached.0422

So let's see: this one, two, three, four, five, six carbons; so this is a hexane derivative.0429

We need to number those carbons; we can either start from this end or start from this end.0438

But because this is closer to the first group--we would get a group on carbon 2; we will number from there--one, two, three, four, five, six.0446

Again we have methyl here... we have two methyls; we have a methyl on carbon 2 and a methyl on carbon 3.0459

Rather than list those repeating substituents separately, our names would get very long, very cumbersome.0464

What we do is we take the common substituents and we group them together; and we call it instead a dimethyl.0471

And what we do is we list where those two methyls occur; one is at carbon 2, one is at carbon 3; so we call it a 2,3-dimethyl... a 2,3-dimethylhexane.0477

Now we are going to put a comma in between the numbers just like you would if you write the number 1,000 or 1,000,000; put a comma between numbers and always a dash between numbers and letters.0493

These rules are using the IUPAC nomenclature; in addition to the IUPAC rules, there are a small number of very commonly used names for commonly seen groups; we do need to be familiar with these as well.0504

For example, if you think about a three-carbon chain that you want to attach to a parent, there is two possible points of attachment.0523

You can either attach it from one of the end carbons; so you would end up... if this is your parent, you would have a CH2CH2CH3 substituent; we call that a propyl group.0534

Its common name--it is called an n-propyl just because it's a normal propyl; it is a normal straight chain carbon.0550

If you attached at the middle carbon instead, the group that you've attached would be a CH with two CH3s on it.0558

This is a different arrangement; this is an isomer of the original arrangement so we call this isopropyl.0567

You may have heard of the word isopropyl when something like isopropyl alcohol is an astringent that you might find in your medicine cabinet; and it means you have an isopropyl group.0576

If we come back to this first structure, this 2-chloropropane also has an isopropyl group.0588

It is a three-carbon chain with something attached to the middle carbon; and so a common name for this compound could be isopropyl chloride.0593

Isopropyl alcohol would have an OH group attached in this position.0612

There are a few common names that you will need to be familiar with; isopropyl is one example.0618

Another commonly encountered substituent is if we had a four-carbon chain that we wanted to attach.0624

Now again if we attach just at the first position... so this was the end position; this was the iso position.0632

Here if we attached at the first carbon, we would have a CH2CH2CH3; so just a normal butyl group; so this is called an n-butyl.0639

And if we were to attach at the second carbon which is described as a secondary carbon because it has two carbons attached, we would get the isomer that is known as sec-butyl.0656

What would that look like?--you have one carbon... I'm sorry, you have a three-carbon chain CHCH2CH3 with one carbon group attached.0670

Here you see we have a four carbon chain that is attached at the second carbon or the secondary carbon of that.0683

This group is known as the sec-butyl group... this is known as the sec-butyl group.0690

Again you could have sec-butyl alcohol or sec-butyl chloride and so on.0696

Finally, if we... we could have another arrangement of carbons like this--of four carbons; so these are commonly encountered.0703

If we attach at this middle carbon, this middle carbon is described as a tertiary carbon because it has three carbon groups attached.0712

That is where the name tert-butyl comes from; we use the prefix tert- to describe one carbon with three methyl groups attached to it.0725

This is still a butyl group because it has four total carbons; but we've attached at the middle carbon with this arrangement; this is called tert-butyl.0739

Or you could just call it t-butyl; sometimes we just use the first letter of the abbreviation; so tert-butyl.0751

The last possible arrangement for four-carbons is if we attached over here; this one is known as iso... the isobutyl.0759

What does that look like?--it has a CH2... it has a CH2.0771

Then we have this isopropyl group; so isobutyl is kind of like an isopropyl with an extra carbon.0776

So then we have what we saw for isopropyl; and this is called isobutyl.0783

So just a brief introduction onto some common names that we will be encountering when we take a look at a lot of the names that you are going to be encountering throughout your reading.0791

What would we do if we had a slightly more complex structure?--let's take a look at this one.0806

We might have a line drawing.0818

Looks like we have a one, two, three, four, five, six, seven, eight-carbon chain here.0827

You might be tempted to take that as your parent.0832

But if you look more closely, you see you have a one, two, three, four, five, six, seven, eight-carbon chain in that direction as well.0835

How do we distinguish between these two?0843

We come back here, and if we see that if there is a tie between two possible carbon chains, we are going to pick the one with the maximum # of constituents.0845

We are going to take the more complex path here... we are going to take the more complex path to have a simpler name.0855

Now we need to number our chain; if we number from this end, we get our first substituent at 2 and then the next one is at 3.0873

If we number from this end, we get our first substituent at 2 and our second substituent at 2; so that is going to be a better choice.0881

So this is carbon #1, 2, 3, 4, 5, 6, 7, 8; so this looks like an octane derivative.0889

What does this octane have attached to it?--well, this is where it is very useful to draw a circle around your parent chain because now you can see all the other groups that you need to account for.0905

We have a chlorine at 7 and a chlorine at 6; we will combine those together because it is the same group; we have a 6,7-dichloro... we have two chloryl groups.0915

At carbon 3, we have a two-carbon chain; a two-carbon compound is called ethane; so a two-carbon substituent is called ethyl; so on carbon 3, we have an ethyl.0936

At carbon 2, we have... what is this sticking out here?--it must be just a one-carbon group so we have a one-carbon... we have a methyl here and a methyl here.0951

Again, we have two methyls so we are going to combine them; we are going to call this a 2,2-dimethyl... a 2,2,-dimethyl.0961

If you are saying that it's a dimethyl, that means you have two methyl groups so there has to be two numbers appreciating that--showing where both those methyls are.0973

Here they happen to be on the same carbon so we call that a 2,2-dimethyl.0980

Now how do we organize all this information--we are going to just alphabetize it.0985

We are going to list... when you alphabetize, you ignore the prefixes that you added; so you are going to ignore the di- in this case.0991

The first letter that would come first is the C for chloro; so we would have a 6,7-dichloro... took care of that one.1002

Then we have an ethyl and a methyl; ethyl comes first; then we do a dash 3-ethyl... took care of that one.1014

Now we have our methyl; so then we go -2,2-dimethyl; and then we go right into octane; no space there.1022

You can see these names can get pretty long pretty quickly; this is called 6,7-dichloro-3-ethyl-2,2-dimethyl octane.1033

Let's take a look at the molecule formula that we expect for an alkane and something known as a degree of unsaturation.1046

A general formula for an alkane is CnH2n+2.1054

If we have that formula, we describe that as being a saturated hydrocarbon--that means we have the maximum # of hydrogens.1061

Being saturated describes the relationship: it is saturated with hydrogen atoms.1072

For example, if we have heptane... using this formula we could determine the molecular formula for heptane.1079

Heptane means that we have seven carbons; and so how many hydrogens are there?1087

Must be 2n+2; so 2n is 14; plus 2; so the formula for heptane is C7H16.1094

That is another very good formula to know CnH2n+2; that is going to come in handy.1109

Why does it always end up being 2n+2?--well, let's take a look at just a regular carbon chain and let's think about how many hydrogens this carbon chain is going to require.1116

We know that a carbon is going to want four bonds; so every one of these carbons has two hydrogens.1127

You will see that we always have twice the # of hydrogens as we do carbons; but the structure isn't complete, is it?1133

At the end, we need to cap it off with a hydrogen on each end; and that is where we get our plus two; 2n+2.1141

It turns out that no matter how I arrange these carbons or if I had ten carbons and put them all different connectivity, we are always going to have that same number of hydrogens.1149

What if I wanted to add a ring however?--what if I wanted to connect the ends of these carbons?--what would I have to do?1160

I would have to remove a hydrogen here and remove a hydrogen here in order to connect these; so addition of a ring is something that causes me to lose two hydrogens.1168

What if I wanted to add a pi(π) bond to this structure?--again in order to form a double bond here, I'd have to remove a hydrogen from each carbon.1182

The addition of a π bond also causes a loss of two missing hydrogens.1193

So when we inspect a formula and we identify that there are two missing hydrogens--that gives us an important clue.1197

Every two missing hydrogens is called a degree or a site of unsaturation; we would describe that as having one DU--if a formula had two missing hydrogens.1206

For example, let's took a look at the formula C9H16 and ask how many degrees of unsaturation there are.1218

A lot of textbooks have pretty complicated formulas for these; and really the only formula you ever need to know is this one right here.1227

As long as you know this formula, doing these types of problems is very straightforward.1234

The question you ask yourself is: if it was saturated, what would the formula be?1238

Well, there is nine carbons; so how many hydrogens does that require?1244

2n+2; so 9 times 2 is 18; plus 2 is 20; there is our 9 times 2 plus 2.1250

If it was saturated, our formula should be C9H20; but it is not; it is actually C9H16.1263

All we have to do very simply is compare those two formula; and what do we find?--there are four hydrogens missing.1270

Because every two missing hydrogens is one degree of unsaturation; four missing hydrogens means we have two degrees of unsaturation.1284

Let's try another one--how do we determine the degrees of unsaturation if our formula contains something other than carbons or hydrogens?1296

How about a halogen?--if I wanted to put a halogen on this structure, what would I have to do?1305

I would have to remove one of the hydrogens and put a halogen in its place; because just like hydrogens, halogens require just one sigma(σ) bond.1310

Every time we see a halogen, we are going to count as a hydrogen; we are going to count it as if it were a hydrogen because they take the same place.1320

If we see an oxygen in the formula, we get to ignore these; it turns out that adding an oxygen to this structure has no effect on the # of hydrogens.1331

If you think about an oxygen, it can form two bonds.1340

If I wanted to put in an oxygen here, I would just squeeze it in between one of the bonds that are already here; and I would not have to replace any hydrogens.1345

So I get to ignore the oxygen; and so that means this formula is the equivalent of having C6H12.1352

Because we drop the oxygen and we included the chlorine with our hydrogen count; and now we proceed as usual.1364

What do we do?--we ask: if it was saturated, what would the formula be?--for 6 carbons, we need 14 hydrogens; 2n+2.1372

We compare that to the actual formula C6H12; and we see that there are two missing hydrogens.1384

Does that mean we have two degrees of unsaturation?--no, every two hydrogens missing is one DU.1393

That is how we can work with a formula of an alkane or a related compound to determine unsaturation.1403

You could even look at a structure and determine the degrees of unsaturation.1410

Without considering the formula, let's take a look at the structure of benzene and determine how many degrees of saturation are there.1415

Well, a degree of unsaturation is defined as either a ring or a π bond; because those are the structural units that cause hydrogen to be missing.1423

What does benzene have?--it has one ring; plus one, two, three π bonds; so it must have four DU.1436

So determining degrees of unsaturation given a structure is very simple; we just count up the rings and the π bonds.1451

If you wanted to check the formula and practice your calculation there and confirm that based on the formula you would also determine that it is four DU.1457

The benzene formula is C6H6; each of these carbons has just one hydrogen attached.1468

So it is C6H6; and if you do your calculation, you should come again with four DU for benzene.1474

One way that understanding these degrees of unsaturation can be very helpful is if you have an exercise such as the one shown here.1483

If I asked you to draw the isomers of C5H12, the very first thing you should do is calculate the DU.1490

That is going to tell you something about the structure; so let's do that.1497

If it was saturated, what would the formula be?--for five carbons, we need 2n+2; we need twelve hydrogens.1500

Guess what?--our structure has all twelve hydrogens; so that means there are zero DU; there are no degrees of unsaturation.1513

What clue does that give us about our structure?1522

It tells us that all isomers of formula C5H12 can have no rings and they can have no π bonds... no rings and no π bonds.1526

Because those structural elements would not allow twelve hydrogens to fit onto the structure.1542

This frees us from ever having to count the hydrogens in our structure.1548

All we have to worry about now are the carbons; so let's deal with our five carbons; how can we put them together?1552

One way is to connect them all in a straight line; this would be one isomer of C5H12.1559

I know that when I fill in the hydrogens, I will have twelve; I don't need to do that initially while I am working this problem.1567

A systematic way of approaching the problem would be to say--OK, well how about having a four-carbon chain?--and then taking that one extra carbon and attaching it somewhere on that chain.1575

What if I attached it to this first carbon?--what do you think about that?--does that look like a new isomer of C5H12?1586

Well, no; because this is really the same structure I've drawn; it is still five carbons all in a line.1594

Just because I've drawn it differently on the page doesn't mean it is something new.1600

That is something you are really going to have to be on the lookout for when you are drawing isomers--that you don't have any repeat structures.1604

But if I had four carbons and attached it to the second carbon, that would be a unique carbon chain from this; so that would be a new isomer.1611

Again I am guaranteed that they would have 12 hydrogens when I fill in all the hydrogens.1621

How about four carbons and then I move it over to the third carbon--that extra carbon?1626

Wow, that looks like it is a repeat of this again, right?--all I did was flip the molecule over.1634

This is where understanding nomenclature can come in handy; because these both would have the same name--this would be 2-methylbutane; this would be 2-methylbutane.1638

Checking the name of a compound is a great way to determine whether you've drawn a repeat or not.1650

How about going to a three-carbon chain and having two extra carbons to work with?--well, I could maybe put one here and put one here.1658

Here is five carbons; do you think that is something new?--or do we still have a four-carbon chain with an extra carbon on the second carbon?--still 2-methylbutane.1671

Three carbons and maybe I can do it as a two-carbon chain?--nope, it's still a four-carbon chain.1684

So it is going to be... you are really going to have to look very closely.1692

The last arrangement we can have is having the three carbons and then putting both carbons on the middle carbon; this now would be a unique arrangement of the carbon atoms.1695

It is just these three possible isomers; they are three isomers; they are all C5H12.1706

I was able to do this problem so much more quickly by just thinking about degrees of unsaturation and not ever counting out my hydrogens.1715

You can go ahead and fill in those hydrogens and convince yourself that you have 12.1722

But what I know immediately is that I don't have to consider a structure like this--how about if I put the five carbons in a ring?1727

Could that be one of my isomers?--it can't be because it has a ring; and that means it is not going to be C5H12.1736

It is going to be C5H10 because putting in a ring causes it to lose two hydrogens.1743

So very useful to know this technique when you are working on isomer problems.1751

Let's talk about how alkanes will behave; what sort of physical properties will they have?1759

Alkanes just have carbons and hydrogens so they are going to be nonpolar molecules.1765

That makes them not very soluble in water... not at all soluble in water because water is a very polar molecule.1771

We know like dissolves like; so we can describe alkanes as being hydrophobic... as being hydrophobic because they have very poor interactions with water.1779

They are isolated from petroleum reserves and crude oil.1794

Part of the distillation process in the refinery separates out the alkanes based on their boiling points and so this is where we get our alkanes commercially.1798

It turns out that alkanes are fairly unreactive; remember these have all strong σ bonds.1810

An alkane can't have any π bonds; it has no other atoms in there other than carbon and hydrogen.1818

Because it has no π bonds and it has no lone pairs, there really aren't too many reactions that they are going to want to undergo.1827

There are few exceptions; one reaction is that alkanes can be used as fuel.1840

In other words, it can undergo combustion; and that of course is what we do with many of the alkanes we get from crude oil.1846

If you looked at the names, propane is the fuel we use for our gas barbeques; methane is the fuel we use to heat our homes; butane are for disposable lighters; octane is a component in gasoline.1855

So we might be familiar with many of these alkanes in our everyday lives because of their role as being a fuel.1875

There is a single reaction that alkanes can undergo that we typically study in organic chemistry--is called a halogenation reaction.1882

That is where we take an alkane, and we convert it to an alkyl halide.1890

We replace one of the hydrogens on the alkane with a halogen like chlorine or bromine; and that is one of the reactions we will be studying for alkanes in just a bit.1896

Let's talk about their physical properties; here we have a series of alkanes.1907

We have a three-carbon chain and then a six-carbon chain and then a thirty-one carbon chain.1911

What do we expect?--what do we observe happening here?--we see an increase in our boiling points.1917

If you have a boiling point of -42 degrees, that means it is going to be a gas at room temperature.1923

Room temperature is somewhere around 20 degrees C so this is going to go to a liquid form all the way down at -42.1930

This three-carbon chain is propane, and we know propane is a gas; that makes sense.1939

When we have six-carbon chains, we now have a boiling point of 69; so hexane is a liquid.1944

That can be used as a solvent; again components in gasoline; we have hexanes in there so that is a liquid.1951

When you have a boiling point above 300 degrees, that means it is going to be very hard even to melt it and then to boil it.1961

This is a solid; it is a waxy solid; kind of like beeswax or candle wax might have a formula like this; very, very long carbon chains; completely hydrophobic; greasy, waxy, that sort of thing.1970

So what is the trend here? What explains this increase in boiling points?1986

Simply as we increase our molecular weight... they all have the same polarity of course, they are all nonpolar.1993

But as you increase your molecular weight, you increase your surface area.1998

You increase your van der Waals attraction or London forces; and that is going to increase your boiling point.2007

So the trends we saw in looking at the various intermolecular nonbonding interactions.2013

How about the shape of alkanes?--what do they do look like in three-dimensions?--we can have different shapes known as conformational isomers.2023

I put isomers in quotes here because these are not isomers in the traditional sense of isomers that are non-interconvertible unique compounds.2034

Conformational isomers (also called conformers) can be interconverted; and so that is why I prefer not to call them isomers; I prefer to call them conformers instead.2045

The way they are related is they are structures which differ only by rotation about σ bonds; so conformers... conformers are different forms of the same molecule.2060

They are interconvertible; because they way we go from one to another is simply by rotation around a σ bond.2075

For example--conformations of ethane; if we take a look at an ethane molecule, we have just a two-carbon structure.2080

This is a CH3 (one, two, three); this is a CH3.2089

The various conformations that ethane can have are these: we can simply rotate around this carbon-carbon bond; and in doing so, this molecule is going to have a different 3D shape.2093

The relationship of this conformer to this conformer--they are called conformational isomers or conformers.2104

I have shown here examples of two extreme conformations; one conformation has two hydrogens pointing up in the same direction.2113

If we rotate this just 60 degrees, we will see in our 3D sketch that one hydrogen is pointing up and one is pointing down.2123

Or we can rotate it this way and get that same conformation where one hydrogen is up and one hydrogen is down.2132

We have names for these conformations; when the two hydrogens in the plane are pointing up--we call this the eclipsed conformation.2139

When one is up and one is down--we call this the staggered conformation.2150

These are rapidly interconverting... rapidly interverting conformers; so these are not two different molecules; it is simply one molecule that is rotating around very rapidly.2157

One way that you can really see why we call these eclipsed and staggered conformations is--when we view the molecules not sideways like we did in the 3D sketch.2175

But we view it in this way--where we are viewing down the carbon-carbon bond.2183

When we do that now the way we are going to see the eclipsed conformation is when the three groups in the front exactly align with the three groups in the back.2189

So this has one straight down... or they both have one straight down or maybe they both have one straight up.2199

We called this the eclipsed conformation; just like the solar eclipse or lunar eclipse or when these things line up with one another.2206

And the staggered conformation is when you have the bonds in the back are intersecting the bonds in the front; and so it goes front, back, front, back; and they are staggered in that way.2212

This point of view is called a Newman projection; it is a very valuable projection.2224

The way we can see that is by standing over here and viewing the molecule like this: looking down the C2C3... I'm sorry, the carbon-carbon bond.2228

What do we see on this front carbon?--on this front carbon, we see a hydrogen pointing straight up; and then we have hydrogens down one is to my right.2240

If I'm looking here--the wedged bond is to my right and the other one is to my left; so this is what we see on the front carbon.2252

What do you see on the back carbon?--well, the back carbon you see the exact same thing--there is a hydrogen straight up and the other two hydrogens are down into the left and right.2263

The way we show the back carbon on a Newman projection is we draw it as a big circle so that we can see them both.2270

So this is the back carbon, and this dot is the front carbon.2278

The back carbon in this eclipsed conformation... we recognize that the back hydrogen is exactly behind the front hydrogen.2288

But what we do is we tilt it just a little tiny bit so that we can see it; so it is visible.2296

So in our drawing we move it slightly; but we keep them very close to each other because we recognize that in fact they are exactly aligned.2302

This is what the eclipsed conformation looks like in a Newman projection.2313

If we rotate the front carbon slightly like we did here... so we rotated around this carbon-carbon bond to get this structure.2318

Now by rotating it 60 degrees, we take this front hydrogen and move it 60 degrees clockwise; this front hydrogen and this front hydrogen--all three groups rotate as we twist the molecule.2331

What happens now is--on this front carbon when we take the same perspective... now on the front carbon, we have a hydrogen pointing straight down; and the other two are up and to the right and left.2345

On the back carbon, we see a hydrogen pointing straight up; and then the other hydrogens are down to the right and left.2358

So here we see the staggered conformation--a little easier to see in this Newman projection.2367

Are these conformations equal in energy?--they are not; the eclipsed conformation is higher in energy.2374

It is less stable because of the interactions between the electrons in the CH bond in the front and the CH bonds in the back being perfectly aligned.2385

We get some interactions there; we call that a torsional strain in having those groups aligned.2396

When they are spread out, we have a staggered conformation which is lower in energy.2408

While the staggered conformation is lower in energy, again, this is just rapidly rotating, freely rotating around quite easily.2415

Let's call this eclipsed conformation A and the staggered conformation B; and what we can do is we can trace the energy of this molecule as it goes through the various conformations.2425

If we start with the A conformation which is staggered, a 60 degree rotation... again if we are rotating, it looks like we are rotating this front carbon because the back carbon stays the same.2442

We go from being staggered to being eclipsed; that's structure B.2452

Another 60 degree rotation would bring me right back to another staggered conformation; it will bring me right back to a conformer that is equivalent to A.2456

And so on; the next rotation brings me back to B, and so on.2466

So if we were to trace our energy curve, at 0 degrees initially, we would be at staggered conformation; that is a low energy conformation.2470

Then after 60 degrees, we will be at a higher energy conformation--the highest energy conformation in fact; the maximum energy you can have; the least stable is when it is completely eclipsed.2481

But then as you continue rotating, you come back down to your staggered conformation and then back up to eclipsed; down to staggered and so on as you rotate.2494

If you were to track just a single hydrogen all the way through 360 degrees, you would come back to A.2507

What happens if you trace the energy of this?--the staggered is the absolute most stable conformation.2514

As you start to bring those hydrogens closer and closer and closer, they become eclipsed and then we are at the maximum conformation energy.2520

Then as they slide past one another, then we start to decrease in energy and we go down to a fully staggered and so on.2527

We go up to eclipsed and down to staggered and up to eclipsed; and this is what our energy diagram looks like as we rotate through the various conformations of ethane.2534

Butane is a more interesting molecule because instead of just having two carbons and three hydrogens on the front carbon and back carbon.2550

If we take a look at butane which has four carbons... if we view it again as a Newman projection, take a look at what is going to happen.2560

As you do your conformations, what you can see pretty quickly is that we have a methyl group on the front carbon and a methyl group on the back carbon.2571

That relationship of those two methyls is continuously changing as we rotate it 360 degrees.2581

So what do you think is going to be the absolute worst conformation of butane to have?2586

Looks like it is probably right here where those two methyl groups are exactly aligned to each other; they are eclipsed with each other.2592

In fact, you can even see that they are crashing into each other; we will talk about that in a second.2598

And what would be the best possible conformation--the lowest energy?2602

It is going to be the one where these large methyl groups are as far apart from each other as possible; so we will take a look at that as well.2606

For the Newman projection, what we do for butane--the most interesting point of view is to look down the carbon-carbon bond between the middle two carbons; so we call that viewing between the C2-C3 bond.2615

Looking from this perspective, what do we see on the front carbon?--we see a methyl group pointing straight up.2632

So we have a methyl group pointing straight up, and we have hydrogens down into our right and left.2641

What do we see on the back carbon?--we see a methyl group going straight down.2647

This line now is drawn from the circle because the circle represents the back carbon.2651

Then we have a hydrogen up into the right and up into the left; so this is a Newman projection of butane.2656

If we were to trace the energy as we go from one conformation to the other, let's take a look at the forms that we are going to have.2671

We start out in this first conformation where the methyl groups... first of all, it's a staggered conformation and the methyl groups are as far apart from each other as possible.2678

When we rotate 60 degrees, what we are going to do here is we are going to rotate the front carbon clockwise.2687

As usual, that is going to bring us from a staggered conformation to an eclipsed conformation.2694

Continued rotation brings us to the staggered conformation; we see our methyl group traveling down.2700

Now it is going to be eclipsed where it is at the bottom; and it is staggered again; and then it is eclipsed.2705

Then our final rotation is going to bring us back to our first structure A; so our last rotation to get 360 degrees brings us back to A.2710

We have names for these staggered conformations.2722

When the two methyl groups are as far apart from each other as possible, we call that the anticonformation; anti meaning opposite--they are 180 degrees from each other in this dihedral angle.2725

When the two methyl groups are right next to each other, we call this interaction a Gauche interaction; let me write the name down first--Guache.2737

What happens in a Gauche interaction is we start to get some interaction between the bulky methyl group on the front carbon and the methyl group on the back carbon.2748

We describe that interaction as steric hindrance or just sterics for short--and this is the interaction we have between very large or bulky groups.2759

It is not a good thing to have large groups near each other; that will cause some instability--this steric hindrance; so a Guache conformation has some steric hindrance.2768

This is another Guache conformation--when the two methyl groups are in adjacent positions; wWe describe that as being Guache; there is two Guache conformations.2781

When we look at our three staggered conformations--A and C and E, what is going to be the most stable conformation?2793

The best one is going to be the anti where the methyl groups are as far apart from each other as possible; so let's put that on the lowest possible level.2801

Then when we come over to C... if we imagine this A level here--this energy level.2811

When we come over to C, we expect that to be... because there has some steric hindrance, we expect this to be a little higher in energy than A.2820

E has the same exact Gauche interaction that C does; so E is going to be at the same energy as C.2835

Then when we go 360 degrees, we come all the way back to A; and that is full circle.2844

Now let's compare our eclipsed conformations; our eclipsed conformations are all going to be bad; but which one is the worst?2851

Here we have two interactions of methyls with hydrogens; here we have an interaction between two methyls.2857

When our two largest groups are eclipsing each other--that has the worst sterics; and that is going to be the highest energy--eclipsed.2865

We said that the staggered... we mentioned that up here... is the lowest energy.2881

So when we come to our first... when we come to B, it is going to be a high energy conformation.2888

But when we get to D--the eclipsed one, it is going to be the highest energy--the least stable; we are going to put this all the way up here.2896

Then when we come to our final eclipsed structure F, it has the same interactions that B does--the methyls with the hydrogens; so we are going to put that at the same level--the exact same energy as B.2904

So the energy of B equals F; these are the two eclipsed conformations with equal energy.2923

And the energy of C is equal to E; those have equal energies as well.2933

Now when we connect the... when we follow the energy path, we are going to go up to an eclipsed conformation, back down to a staggered.2941

Up to the worst eclipsed, down to a staggered, up to eclipsed, and back down to the most stable conformation.2951

When we follow this path with our model, we are starting with the front methyl group straight up and the back methyl group straight down.2961

Then we are going to be rotating this clockwise; so we are going to go up in energy to eclipsed; and then back down in energy to a staggered.2971

But this staggered is not going to be as good because we have this Guache interaction; we have a little steric interaction between those two methyls.2980

Then we are going to continue and we are going to go up in energy to the highest eclipsed because we have these two methyl groups interacting with steric hindrance; so that is the worst.2987

But as they swing past each other, we go back down to a staggered; and then back up to an eclipsed; and then back up to our best staggered.2996

We are always going to be alternating in energy between maxima and minima; what is real important is to note that all eclipsed conformations are high energy.3005

Even the best eclipsed is still bad compared to any of the staggered; and all the staggered ones are low energy; so these are some things to point out.3020

You also want to keep in mind that there is a significant difference between the eclipsed ones and the staggered ones.3035

The difference between the various eclipsed conformations is on the order of 1 kcal where the difference in energy between the worse eclipsed and the best staggered is about 5 kcal.3042

Likewise the difference between the Guache and the anti is around 1kcal; so not a huge difference between these staggered energies or between the eclipsed energies.3066

But between the staggered and eclipsed, that is where you want to see the biggest jump when you are trying to do these sorts of energy diagrams for conformations.3076

If we take a look at cycloalkanes, when we try and form a ring and we try and do it with either a three-carbon chain or a four-carbon chain, and we try to form it into a ring.3088

Even with this model, you can see that we are meeting some resistance; that is not an easy thing to do; in fact, that is a good way to break a model kit.3102

The problem is that if we are to try and form a triangle--a cyclopropane, this bond angle would have to be 60 degrees in order to be a triangle.3113

It is very difficult for it to make that; carbon wants to be 109.5 because it is sp3 hybridized; and it can't do that.3128

Even with a cyclobutane, this would require a 90 degree angle; and that would also squeeze or compress that angle together; we describe that strain as angle strain.3136

In addition, when you take a look at the structures... if you do form this and you look at the Newman projection, you see that the front hydrogens exactly line up with the back hydrogens.3149

We call those eclipsing each other; and we describe that as torsional strain; and there is no way to alleviate that unlike the regular butane where we can rotate in various conformations.3162

This is locked into this rigid structure and so there is no way to get around that.3173

So when you take a look at cyclopropane, you have this wedge and dash hydrogen and this wedge and dash hydrogen; and they are all eclipsing each other; and so that offers some torsional strain as well.3177

So both cyclopropane and cyclobutane are unstable molecules.3200

Together we describe this combination of torsional strain and angle strain as having a high amount of ring strain; we call it ring strain when we try to form these small rings of three and four members.3210

It is possible that these compounds do exist but they are very high energy; they are highly reactive and difficult to form.3229

When you form a five-membered ring, however, it is going to be easier to bring these together because we have more room.3236

You can see actually even with this model kit it is quite easy to bring these ends together and connect it.3245

This has very little strain; the angles can naturally be very close to 109.5.3251

If we were to hold the molecule completely planar, then we would have this eclipsing interaction again with the front and the back.3258

But if we bend the molecule slightly, we can alleviate some of that torsional strain and get some better interactions.3265

This conformation is known as the envelope conformation--where you have four carbons in one plane and then the fifth carbon is bent out of that plane; and that is what cyclopentane looks like.3273

Cyclohexane is a compound that we will spend quite a bit of time studying.3298

Because when you have a six-membered ring and you bring it together, the structure you end up with has absolutely no ring strain.3304

It is completely flexible; it is just as flexible and just as stable as it would have been if it were in a straight chain; and so six-membered rings are very common in organic chemistry.3312

What we will find is that because this can rotate about the σ bonds, there are various conformations that cyclohexane can have; the two extreme conformations are shown in the drawing here.3325

One is called a chair conformation, and that is where you have--four carbons are in one plane; that is kind of like the seat of the chair; and then you have this carbon pointing up and this carbon pointing down.3339

Or vice versa; you have four here and the one on this side is pointing down; the one on this side is pointing up; this is called a chair conformation.3360

The other extreme conformation is where both carbons on either end are pointing in the same direction.3368

Here we have our four carbons are in one plane, and then we have this carbon up and this carbon up; this kind of is a boat shape; we call this the boat conformation.3374

As shown here with this equilibrium, you can see that it is favoring the direction of the chair; the chair is the more stable conformation; and the boat is less stable.3383

There are a number of reasons that the boast is less stable.3399

One is that if you look at the hydrogens on these top carbons, you see that they are facing in near one another; and so we have some steric interactions; these are called flagpole hydrogens.3402

In addition, if you take a look at the hydrogens on these two front carbons, you see that these are eclipsing; so we have some torsional strain as well.3421

In fact, the boat is so unstable that a cyclohexane really never hangs out in a boat conformation.3436

What happens instead to alleviate some of these interaction rather than having these two hydrogens pointing in right towards each other.3443

It twists a little bit to avoid that interaction; we call that the twist-boat conformation.3450

You will see this drawing sometimes as a way to represent something that is not as good as a chair but not quite as bad as the boast.3455

These two conformations are interconverting because we can rotate around; and so the chair kind of goes through a twist boat as it is going to the boat and back to the chair.3463

Drawing a cyclohexane chair is going to be a skill that you want to develop in organic chemistry; and let's go through how to do that.3480

The first thing you want to do is draw a wedge; draw a little angle here.3489

Then you are going to draw two bonds coming down that are parallel to each other; and then you are going to draw another wedge pointing up.3495

Wherever this bond was drawn, this bond is going to be parallel to that; and however this bond was drawn, you are going to draw a bond parallel to that.3506

This is the general form that a chair is going to take; with some practice, you get something good there.3516

What you want to avoid is just drawing a zigzag thing like this because then it is going to be very hard to show any detail on that chair.3524

Now what you will notice when you look at a chair conformation... notice that I've put some different colored atoms on this to illustrate the two different types of positions you have on a chair.3532

Some of these atoms are pointing straight up... let me get a good looking... my model is a little too wobbly here.3545

Here you see that the red atoms are pointing straight up and straight down.3554

Notice that the chair is a zigzag; it goes up down, up down, up down, kind of like we draw our zigzag line drawings.3560

Every carbon that is a zigzag up has a hydrogen atom or a position that is straight up; every one that has a zigzag down has one that is going straight down.3567

These are the first ones we should draw onto our chair--this is a zigzag up so it has a hydrogen going straight up; this is a zigzag down so it has one going straight down.3576

And then we go up; and then we go down; and notice that they are alternating up and then down.3589

The perspective that we take is that this carbon up on the top is behind these carbons in the front.3594

We are looking at the chair from an angle; and we are tipping it down a little bit so that these front are downward and the back carbons are the ones that are closer to the top of the page.3602

So we have these six positions that are all straight up and down; we call these axial positions; so let's label these as axial hydrogens.3614

Six that are straight up... I'm sorry, three that are straight up and three that are straight down; those are the easiest ones to put on first.3625

Then on each of these positions, each of these is a CH2; so there is another hydrogen on each of these positions but take a look at these.3638

These are all pointing around like the equator of the molecule; these are called the equatorial hydrogens.3646

Notice that none of them are pointing straight out; they are not at a 90 degree; they are either slightly down or slightly up... slightly down or slightly up.3653

When we drawn in the equatorial hydrogens, we take a look at the axial we've drawn and then we know that it is a 109.5 angle; so we draw it slightly down and then slightly up.3664

We could draw these on this end; and then over here we could draw slightly down and then slightly up.3683

Then we have these in the middle as well; this is where we will draw this equatorial hydrogen; and this is where will draw this equatorial hydrogen.3693

Again with practice, you will get better at this.3701

Every bond that you draw... the axials are straight up and down; every other bond that you draw is going to be parallel to some other bond.3704

See that this equatorial is parallel to this bond in this cyclohexane; and in a nicely drawn cyclohexane, you will see that you can see this W here or you can see an M here.3713

Those are some of the features you can look for as you are drawing it and try to decide where to put your equatorial and your axial.3727

A Newman projection of a cyclohexane is interesting because as you view down one carbon-carbon bond, you are simultaneously viewing down the parallel carbon-carbon bond.3734

If we view the molecule in this direction looking down this carbon-carbon bond, we are at the same time viewing this carbon-carbon bond.3749

On this front carbon, I see a hydrogen straight down; and a hydrogen up into my right; and up into my left, I have this CH2.3757

On the back carbon, I have a hydrogen straight up; and a hydrogen down into my left; and down into my right, I have a CH2.3771

There is our Newman projection of the carbon on the left.3786

The carbon on the right, I see a hydrogen straight down and then a CH2 up into my left that is connecting this CH2.3789

On the back carbon, we have a hydrogen straight up; hydrogen down into the right; and down into the left, I have this CH2 that was down into the right from the other back carbon.3806

So a lot to go through pretty quickly; but as you take your time and try it on your own, what this illustrates very nicely is that this is an all staggered conformation.3821

Coming back to why the chair conformation is so stable, not only does it avoid the flagpole hydrogens, but it also avoid the eclipsing interactions that you have with the boat.3830

Everything is very nicely staggered.3842

When you draw a chair conformation or you look at a chair conformation for cyclohexane, what we will find is that there is actually two possible chairs that any cyclohexane derivative can have.3851

Right now the molecule I have has all the red atoms in the axial position.3863

If I perform a little magic trick here, I can convert it to the conformation where all of the white atoms are in the axial position; what I just did there is called a chair flip.3869

I've drawn a model here where I just have an X representing the axial positions.3883

What happens in a chair flip is that you take this end carbon and flip it up; and you take the other end carbon and you flip it down.3889

Let's take a look at that with the model; there is four carbons in the middle--that is the seat of my chair.3898

I take the one on the far left that is down, and I bring it up into a boat conformation temporarily.3910

Then I take the one on the far right, and I bring it down; and I have a new chair.3918

The way we can translate it to the next chair is--let's number our carbons.3926

Let's call this 1, 2, 3, 4 (those are the front carbons) 5, 6.3929

This carbon that is on the far left is still on the far left; he was pointing down, but now he is pointing up; this is 1.3937

Then because we numbered counterclockwise here, we are going to continue numbering counterclockwise.3944

The front carbons are still in the front; 1, 2, 3, 4, 5, 6; and on carbon 1, the X was in the down position.3949

If you think of a cyclohexane, if you flatten out the ring--totally flatten it out, six of the atoms are pointing up and six are pointing down, right?3965

Because he started out in the down position, he is still going to be in the down position; where is the down position?--it is right here.3975

Carbon 2 has an X up; carbon 2 still has an X up; and they alternated--down and then up, down and then up.3983

Look what happened: all of our axial groups are now equatorial; and all of our equatorial groups have become axial; so this called a chair flip.3993

Let's see an example of it; here we have methylcyclohexane.4005

If we wanted to do a chair flip of methyl cyclohexane, what we do is we would take this carbon on the left and bring him up; bring the carbon on the right and bring him down.4008

Then the chair that we have cannot have the same shape anymore; instead of starting down and going up, it is going to start up and go down; and then we draw our two parallel lines.4019

So this is our new chair; they should have this mirror relationship to one another.4035

This carbon on the far right is now this carbon on the far right; the methyl was up; the methyl still is up.4042

Where are the two positions on this carbon?--because it is a zigzag down, that means it has an axial straight down and an equatorial slightly up.4051

Where does the methyl go?--he was up and in the axial position; now he is up and in the equatorial position.4064

So these are the two chair conformations of methylcyclohexane.4071

The next question we can ask is: are each of these conformations equal in energy?--and the answer is no.4076

This is the more stable conformation; and this is the less stable conformation.4083

That is because the large methyl group has some sterics when it is in the axial position as is here; it has steric interactions called 1,4-diaxial interactions.4093

When we have an axial group, it sees these axial hydrogens; and they can crowd each other and have some sterics; so the sterics are called 1,4-diaxial.4117

That makes this less stable; so this equilibrium lies in the forward direction here where the larger group is put in the equatorial position.4129

Let's just try one example of this; how about if we are asked to draw the chair conformations of cis-1-t-butyl-4-methylcyclohexane?4142

Cis means that the groups are both up or both down.4151

Let's draw a chair; let's just draw it flat first.4159

In one position, we have a methyl group; in the other position, we have a tert-butyl group.4167

Just so we get oriented, this is what we are trying to draw.4174

We want to draw chair conformation; so let's draw one chair... OK, and... just trying to straighten out my lines here.4178

Let's makes these our end carbons the opposite carbons here.4192

Here we have a methyl group up; so let's put our methyl group up on this end.4196

Then on the far end on the fourth carbon, we have a t-butyl group up; that would be one chair conformation.4203

The other chair conformation where we bring this down and we bring this up--would look like this; here is our other chair conformation.4215

Our methyl group is up here in the axial position; and our t-butyl group is up here in the equatorial position.4229

What if we have to make a choice?--we know that large groups prefer to be in the equatorial position.4240

But how do we decide if they both can't be in the equatorial position?--it would be great if they could, but they can't here.4246

Because the tert-butyl group is a larger group, the larger group prefers the equatorial.4253

Larger group prefers the equatorial position; so our equilibrium is going to lie in this direction.4269

Remember the problem with having the larger group in the axial is that this group crowds the other axial groups--hydrogens in this case; called 1,4-diaxial interactions.4274

If you take a look at what a methyl group looks like compared to a tert-butyl group, a tert-butyl group is notorious for being a very bulky group; it has three methyls attached to a single carbon.4285

So this would have a lot of steric hindrance where a small methyl group wouldn't mind as much being in the axial position.4296

We can look at a variety of substituents and see what their preference is for being in the axial versus equatorial position.4303

We call this the A value--it is the energy difference between the axial and equatorial.4313

Of course, for a hydrogen, there is no difference; a chlorine is slightly larger, so it has a small energy difference.4318

Methyl and ethyl are close to the same; remember an ethyl group can just rotate out of the way to avoid this interaction.4324

But when you get to t-butyl, look at this huge number; a t-butyl group is so bulky that it essentially locks; we could say that this is locked in this chair.4331

It is so difficult to flip that t-butyl group up into the axial position; so this is a way to lock a single conformation.4343

One interesting example is how about this alkyne--this triple bond group; why is that such a small number?--can you think about the geometry of the triple bond?4350

If I were to put this in an axial position, what is that going to look like?--it goes straight up, doesn't it?4361

So how much interaction is it going to have with these other axial hydrogens?--not very much compared to a tert-butyl group... let's put this on here while I have the model.4371

A tert-butyl group in this position--there is no way you can alleviate that steric strain; so there is a very high energy there.4382

But this is so small because it is linear; and so when we put that in an axial position, it goes straight up; and there are very little steric interactions so it doesn't mind being it.4390

So when we have to make a choice between chair conformations, we are going to pick the one with the largest group in the equatorial position.4411