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Organic Chemistry Alkenes

III. Alkanes, Alkenes, & Alkynes: Lecture 1 | 36:39 min

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Dr. Laurie Starkey

Dr. Laurie Starkey

Alkenes

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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 (20)

	1 answer Last reply by: Professor Starkey Wed Apr 29, 2015 11:38 AM Post by Jinhai Zhang on April 28, 2015 Dear Prof.Starkey: In your cyclohexanol example, if it is five carbon ring, under H2SO4, we have ring expansion, don't we? Do you have a lecture about ring expansion?
	1 answer Last reply by: Professor Starkey Wed Dec 10, 2014 10:32 PM Post by Parth Shorey on December 10, 2014 I understand you said that for OH to be a LG is to have a strong acid, but I'm still confused if that were to apply to Sn1/Sn2 reaction. How does a HCL work doing a back attack, like what happens to the Hydrogen. I just need to see a detain mechanism steps. The elimination I get because you have already showed us that.
	1 answer Last reply by: Professor Starkey Wed Dec 10, 2014 10:33 PM Post by Parth Shorey on December 10, 2014 At 19:46 would H2CrO4 be a good dehydration of the alcohol?
	1 answer Last reply by: Professor Starkey Sun May 12, 2013 7:23 PM Post by Sitora Muhamedova on May 12, 2013 Professor, Sn2 favors 3 degree, how come 1 degree reactions can be favored, and also, if Carbon 1 degree is favored by E1 reaction why would not it be appropriate to imply to our reaction with Bromide?
	1 answer Last reply by: Professor Starkey Tue Oct 23, 2012 8:28 PM Post by Meshari Alabdulrhman on October 20, 2012 Hi Dr.Starkey would you please explain more how to determine reagents and solvents in each reactions.?
	1 answer Last reply by: Professor Starkey Sat Jan 21, 2012 1:03 PM Post by Jason Jarduck on January 19, 2012 HI Dr. Starkey, Would you be able to show the individual 2-methyl-1-butene products.For reactions with HBR with CH2Cl2, Eto-K+, Br2, HBR with roor, NBS with RooR, BR2 please. YOU HAVE GREAT LECTURES I USE THEM FOR STUDYING FOR EXAMS!!!! Thank you
	1 answer Last reply by: Professor Starkey Wed Dec 28, 2011 11:33 PM Post by Rohan Shah on December 14, 2011 Hey Dr. Can you show the mechanism for treating an alcohol with phosphorous oxychloride?
	1 answer Last reply by: Professor Starkey Wed Nov 30, 2011 11:12 PM Post by Anahita Behshad on November 26, 2011 I was wondering if there is sth wrong with these videos,,,I used to watch these with no problem, but now these organic chem videos stop working after few minutes...I tried other videos in bio /math section but didn't have any problem with them :(
	1 answer Last reply by: Professor Starkey Sat Nov 5, 2011 3:50 PM Post by Jamie Spritzer on November 1, 2011 in 28:53 wouldn't the SN1 be major, since the carbon is secondary?
	1 answer Last reply by: Professor Starkey Wed Apr 6, 2011 11:23 PM Post by Billy Jay on March 23, 2011 Hi Dr. Starkey. I have two questions: Are H2SO4, HClO4, HNO3, and HClO3 the only Strong Acids that would be limited to E1 (instead of SN1). The reason I ask is because of the remaining 7 strong acids (HCl, HBR, and HI) all have a conjugate base (weak base) that acts as a strong nucleophile. Also, at around 33:00 you react a primary Alcohol with H2S04 and explain that it would most likely undergo E1 and re-arrange to a tertiary carbocation. Is it also possible for an E2 product to form as well? Is the reason you excluded it because in this case, E2 would be a very minor product since the primary substituted alcohol is unfavorable for E2? Thank you.

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Alkenes

Draw all the products and select the major product for this reaction:

Alkene is more stable if more alkyl groups are attached
includegraphics*Ochem-12-1b.jpg

Draw the product(s) formed from this reaction:

includegraphics*Ochem-12-2b.jpg
includegraphics*Ochem-12-2c.jpg

includegraphics*Ochem-12-2d.jpg

Draw all the products and select the major product for this reaction:

Draw all the products and select the major product for this reaction:

Draw all the products and select the major product for this reaction:

Draw all the products and select the major product for this reaction:

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

Answer

Alkenes

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

Intro 0:00
Alkenes 0:12

Definition and Structure of Alkenes
3D Sketch of Alkenes
Pi Bonds

Alkene Stability 4:57

Alkyl Groups Attached
Trans & Cis

Alkene Stability 8:42

Pi Bonds & Conjugation
Bridgehead Carbons & Bredt's Rule
Measuring Stability: Hydrogenation Reaction

Alkene Synthesis 12:01

Method 1: E2 on Alkyl Halides
Review: Stereochemistry
Review: Regiochemistry
Review: SN2 vs. E2

Alkene Synthesis 18:57

Method 2: Dehydration of Alcohols
Mechanism

Alkene Synthesis 23:26

Alcohol Dehydration

Example 1: Comparing Strong Acids 26:59
Example 2: Mechanism for Dehydration Reaction 29:00
Example 3: Transform 32:50

Organic Chemistry Online Course

I. Introduction to Organic Molecules
	Introduction and Drawing Structures	49:51
	Lewis Structures & Resonance	44:25
	Acid-Base Reactions	1:07:46
	Structures and Properties of Organic Molecules	1:23:35
	Alkane Structures	1:13:38
	Stereochemistry	1:40:54
II. Understanding Organic Reactions
	Nomenclature	1:53:47
	Chemical Reactions	51:01
	Free Radical Halogenation	26:23
	Substitution Reactions	1:48:05
	Elimination Reactions	1:11:43
III. Alkanes, Alkenes, & Alkynes
	Alkenes	36:39
	Reactions of Alkenes	2:08:44
	Alkynes	1:13:19
IV. Alcohols
	Alcohols, Part I	59:52
	Alcohols, Part II	45:35
V. Ethers, Thiols, Thioethers, & Ketones
	Ethers	1:34:45
	Thiols and Thioethers	16:50
	Ketones	2:18:12
VI. Organic Transformation Practice
	Transformation Practice Problems	38:58
VII. Carboxylic Acids
	Carboxylic Acids	1:17:51
	Carboxylic Acid Derivatives	1:21:04
VIII. Enols & Enolates
	Enols and Enolates, Part 1	1:26:22
	Enols and Enolates, Part 2	50:57
IX. Aromatic Compounds
	Aromatic Compounds: Structure	1:00:59
	Aromatic Compounds: Reactions, Part 1	1:24:04
	Aromatic Compounds: Reactions, Part 2	59:10
X. Dienes & Amines
	Conjugated Dienes	1:09:12
	Pericyclic Reactions and Molecular Orbital (MO) Theory	1:21:31
	Amines	34:58
XI. Biomolecules & Polymers
	Biomolecules	1:53:20
	Polymers	45:47
XII. Organic Synthesis
	Organic Synthesis Strategies	2:20:24
XII. Organic Synthesis & Organic Analysis
	Organic Analysis: Classical & Modern Methods	46:46
	Analysis of Stereochemistry	1:02:52
XIII. Spectroscopy
	Infrared Spectroscopy, Part I	1:04:00
	Infrared Spectroscopy, Part II	48:34
	Nuclear Magnetic Resonance (NMR) Spectroscopy, Part I	1:32:14
	Nuclear Magnetic Resonance (NMR) Spectroscopy, Part II	2:03:48
	C-13 DEPT NMR Experiments	23:10
	Two-Dimensional NMR Techniques: COSY	33:39
	Two-Dimensional NMR Techniques: HETCOR & HMBC	15:05
	Mass Spectrometry	1:28:35
XIV. Organic Chemistry Lab
	Completing the Reagent Table for Prelab	21:09
	Introduction to Melting Points	16:10
	Melting Point Lab	8:17
	Introduction to Recrystallization	22:00
	Recrystallization Lab	19:07
	Introduction to Distillation	25:54
	Distillation Lab	24:13
	Introduction to TLC (Thin-Layer Chromatography)	28:51
	TLC Analysis Lab	20:50
	Introduction to Extractions	34:25
	Extraction Lab	14:49

Transcription: Alkenes

Welcome to Educator.0000

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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