Contents 23 Substitution Reactions of Carbonyl Compounds at the a Carbon 880 23.1 Introduction 881 23.2 Enols 881 23.3 Enolates 884 23.4 Enolates of Unsy 23.5 891 A Preview of Rea actions at the a rbon 892 on at ne a Carbo 89 te 23.9 Malonic Ester Synthesis 900 23.10 Acetoacetic Ester Synthesis 903 Key Concepts 906 Problems 908 24 Carbonyl Condensation Reactions 916 24.1 The aldol Reaction 917 242 Crossed Aldol Reaction 921 Directed Aldol Reac n 926 r Aldol ctions 926 Re The Crossed Claisen and Re lated Reactions 930 The Dieckmann Reaction 93 24.8 The Michael Reaction 934 24.9 The Robinson Annulation 936 Key Concepts 940 Problems 941 Amines 949 25.1 25.2 950 952 954 25.5 Spectroscopic Properties 955 25.6 Interesting and Useful Amines 956 25.7 Preparation of Amines 960 25.8 Reactions of Amines-General Features 966 25.9 Amines as Bases 966 25.10 Relative Basicity of Amines and Other Compounds 968 25.11 Amines as Nucleophiles 975 25.12 Hofmann Elimination 977 25.13 Reaction of Amines with Nitrous Acid 980 25.14Sub5 ium Salts 982 25.15C0 upling Reactic of Aryl um Salts 986 25.16 Application:Synthetic Dyes 98Contents xv 23 Substitution Reactions of Carbonyl Compounds at the ` Carbon 880 23.1 Introduction 881 23.2 Enols 881 23.3 Enolates 884 23.4 Enolates of Unsymmetrical Carbonyl Compounds 889 23.5 Racemization at the α Carbon 891 23.6 A Preview of Reactions at the α Carbon 892 23.7 Halogenation at the α Carbon 892 23.8 Direct Enolate Alkylation 897 23.9 Malonic Ester Synthesis 900 23.10 Acetoacetic Ester Synthesis 903 Key Concepts 906 Problems 908 24 Carbonyl Condensation Reactions 916 24.1 The Aldol Reaction 917 24.2 Crossed Aldol Reactions 921 24.3 Directed Aldol Reactions 925 24.4 Intramolecular Aldol Reactions 926 24.5 The Claisen Reaction 928 24.6 The Crossed Claisen and Related Reactions 930 24.7 The Dieckmann Reaction 932 24.8 The Michael Reaction 934 24.9 The Robinson Annulation 936 Key Concepts 940 Problems 941 25 Amines 949 25.1 Introduction 950 25.2 Structure and Bonding 950 25.3 Nomenclature 952 25.4 Physical Properties 954 25.5 Spectroscopic Properties 955 25.6 Interesting and Useful Amines 956 25.7 Preparation of Amines 960 25.8 Reactions of Amines—General Features 966 25.9 Amines as Bases 966 25.10 Relative Basicity of Amines and Other Compounds 968 25.11 Amines as Nucleophiles 975 25.12 Hofmann Elimination 977 25.13 Reaction of Amines with Nitrous Acid 980 25.14 Substitution Reactions of Aryl Diazonium Salts 982 25.15 Coupling Reactions of Aryl Diazonium Salts 986 25.16 Application: Synthetic Dyes 988 smi75625_fm_00i-xxxiv.indd xv 11/17/09 11:21:34 AM