Arrow-Pushing in Organic Chemistry

319 Pages·2008·2.92 MB·English

by  Daniel E. Levy

Arrow Pushing in
Organic Chemistry
An Easy Approach to Understanding
Reaction Mechanisms
Daniel E. Levy

Arrow Pushing in
Organic Chemistry

Arrow Pushing in
Organic Chemistry
An Easy Approach to Understanding
Reaction Mechanisms
Daniel E. Levy
Copyright#2008byJohnWiley&Sons,Inc.Allrightsreserved
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Contents
PREFACE xi
ACKNOWLEDGMENTS xiii
ABOUT THE AUTHOR xv
1. Introduction 1
1.1 Definition of Arrow Pushing 1
1.2 Functional Groups 5
1.3 Nucleophiles and Leaving Groups 8
1.4 Summary 8
Problems 10
2. Acids 19
2.1 What are Acids? 19
2.2 What is Resonance? 20
2.3 How is Acidity Measured? 23
2.4 Relative Acidities 25
2.5 Inductive Effects 29
2.6 Inductive Effects and Relative Acidities 31
2.7 Relative Acidities of Hydrocarbons 33
2.8 Summary 34
Problems 35
vii
viii CONTENTS
3. Bases and Nucleophiles 45
3.1 What are Bases? 45
3.2 What are Nucleophiles? 50
3.3 Leaving Groups 54
3.4 Summary 55
Problems 56
4. S 2 Substitution Reactions 65
N
4.1 What is an S 2 Reaction? 65
N
4.2 What are Leaving Groups? 67
4.3 Where Can S 2 Reactions Occur? 68
N
4.4 S 20 Reactions 71
N
4.5 Summary 73
Problems 74
5. S 1 Substitution Reactions 83
N
5.1 What is an S 1 Reaction? 83
N
5.2 Howare S 1 Reactions Initiated 84
N
5.3 The Carbocation 86
5.3.1 Molecular Structure and Orbitals 86
5.3.2 Stabilityof Carbocations 90
5.4 Carbocation Rearrangements 92
5.4.1 1,2-Hydride Shifts 92
5.4.2 1,2-Alkyl Shifts 93
5.4.3 Preventing Side Reactions 95
5.5 Summary 96
Problems 97
6. Elimination Reactions 101
6.1 E1 Eliminations 101
6.2 E2 Eliminations 104
6.3 How Do Elimination Reactions Work? 105
6.4 Summary 108
Problems 109
7. Addition Reactions 115
7.1 Addition of Halogensto Double Bonds 115
7.2 Markovnikov’s Rule 117
7.3 Additionsto Carbonyls 119
7.3.1 1,2-Additions 119
7.3.2 1,4-Additions 121
7.3.3 Addition–Elimination Reactions 123
7.4 Summary 125
Problems 126