A synthesis of some novel 4,5‐dihydroazepines by the reaction of oxazolium 5‐oxides with 1,2‐dicyanocyclobutene

Abstract

Abstract Heating primary or secondary α‐amino acids in acetic anhydride in the presence of 1,2‐dicyanocyclobutene leads to 4,5‐dihydroazepines via the intermediacy of mesoionic oxazolium 5‐oxides.