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Chemistry of Carbonyl Compounds (McM 19-12). Nucleophilic addition / substitution. May also be acid cat . The Cannizzarro reaction (McM 19.13) Hydride as leaving group!. Conjugate Addition (McM 19.14). Michael acceptor. 1,2-addition, Ex: Alchohols Organolithium. 1,4-addition, Ex:
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Chemistry of Carbonyl Compounds (McM 19-12) Nucleophilic addition / substitution May also be acid cat.
The Cannizzarro reaction (McM 19.13) Hydride as leaving group!
Conjugate Addition (McM 19.14) Michael acceptor • 1,2-addition, Ex: • Alchohols • Organolithium • 1,4-addition, Ex: • Amines • Organocuprates Michael reaction (McM 23.11)
Robinson Annulation (McM 23.13) Ring forming react. annulus (lat.) = ring
E: • - Alkyl halides • Carbonyl compounds (Aldol, Claissen condens.) • - Halides
Michael acceptor Enolizable Alkylation of enolate anions (McM 22.8) Base: Strong, sterical hindrance Ketones, esters, nitriles (Aldehydes: condensation)
Alkylation of 1,3-dicarbonyl compounds followed by decarboxylation
Enamines as enolate equivalents (McM 23.12, Lab ex. 11) Synthesis of enamines (cf McM 19.9)
Reactivity of enamines • Alkylation (alkyl halides) • Conjugate addition (Michael acceptors) • Acylation (acid halides) • Monoalkylation • No strong base
Halogenation of neutral enols (McM 22.3) mainly monohalogenated prod. a-Bromination of acids (McM 22.4)
Carbonyl condensations in nature (McM 21.8, 23.14) Acyl-CoA Acetyl-CoA (Acetyl co-enzyme A) Synthesis of Acetylcholine (neurotransmittor)
Polyesters, polyamides etc (McM 21.9) Acyl subst react Step-Growth polymers (Chain-Growth polymers: Polyenes)