A Novel Darzens-Type Condensation Using α-Chloro Ketimines

Article abstract of DOI:10.1021/jo00254a007

3-Chloro-1-azaallylic anions, generated by deprotonation of α-chloro ketimines with lithium diisopropylamide, reacted with ketones and aldehydes to produce 2-imidoyloxiranes (α,β-epoxy ketimines).This novel aza-Darzens-type condensation allows α-chloro ketones to condense with carbonyl compounds via protection as α-chloroketimines.The aza-Derzens-type reaction with benzophenones as carbonyl substrate proceeded via Favorskii-like rearrangement of an intermediate α,β-epoxy ketimine, the intermediate cyclopropylideneamine being trapped in an intramolecular way.Subsequent ring opening of the bicyclic intermediate adduct according to a so-called abnormal opening furnished rearranged 3-butenenamide derivatives.