Enantioselective Generation and Diastereoselective Reactions of Chiral Enolates Derived from α‐Heterosubstituted Carboxylic Acids. Preliminary Communication

Dioxolanones7and8aand oxazolinones9aderived from pivalaldehyde and lactic acid, mandelic acid, and proline, respectively, furnish chiral enolates of type3by deprotonation with LDA. Reactions of these enolates with alkyl halides, aldehydes, and ketones(→ 8b, 9b, 11–13)are highly diastereoselective. Thus, the overall enantioselective α‐alkylation of chiral, non‐racemic α‐heterosubstituted carboxylic acids(4 → 6)is realized.