Table of Contents
Preface xi
Acknowledgements xiii
Some Help That You May Need xv
What Do You Need to Know Before You Start? xvii
Introduction xix
1 Nucleophilic Addition to the Carbonyl Group 1
Nucleophilic addition: what it is and how it happens 3
Alcohols as nucleophiles: acetal formation 6
Some carbon–carbon bond-forming reactions with carbon nucleophiles: cyanide ion, acetylide ion and Grignard reagents 10
Hydride ion and its derivatives LiAlH4 and NaBH4 Reduction of aldehydes and ketones 17
Meerwein–Ponndorf reduction and Oppenauer oxidation, with a branch program on how to draw transition states 19
Two general revision problems 25
2 Nucleophilic Substitution 29
Substitution: how it happens 31
LiAlH4 reduction of esters 33
Reaction of Grignard reagents with esters 34
Alkaline hydrolysis of esters 38
Acid hydrolysis of amides 39
Summary of acid and base catalysis 41
Reaction between carboxylic acids and thionyl chloride 41
Synthesis of esters and anhydrides from carboxylic acids 43
Review questions 45
3 Nucleophilic Subsitution at the Carbonyl Group with Complete Removal of Carbonyl Oxygen 49
Imine formation from aldehydes and ketones 51
Oxime formation and the structure of oximes 53
Hydrazone and semicarbazone formation 54
Reduction of C=O to CH2 56
Conversion of C=O to CCl2 60
DDT synthesis 64
Chloromethylation of aromatic compounds 65
Review questions 66
4 Carbanions and Enolisation 69
Carbanions 71
Tautomerism 72
Equilibration and racemisation of ketones by enolisation 73
Halogenation of ketones 78
Formation of bromo-acid derivatives 83
Organo-zinc derivatives and their use in synthesis 85
Review questions 87
5 Building Organic Molecules from Carbonyl Compounds 89
Using enols as nucleophiles to attack other carbonyl groups 92
The aldol reaction 92
The Claisen ester condensation 93
Acid catalysed condensation of acetone 94
Self-condensation reactions 96
Elaboration of a skeleton in synthesis 97
Cross-condensations with molecules which cannot enolise 98
Mannich reaction 103
Perkin reaction 105
Stable enols from β-dicarbonyl compounds 108
Knoevenagel reaction 110
Alkylation of β-dicarbonyl compounds 113
Michael reaction 116
Decarboxylation 125
Base cleavage of β-dicarbonyl compounds 131
Cyclisation reactions: the Dieckmann condensation 134
Cyclisation of diketones 136
The dimedone synthesis 137
Ring opening by base cleavage of β-dicarbonyl compounds 141
Revision questions 142
Examples of syntheses: two steroid syntheses 145
Stork’s cedrene synthesis 150
Index 155