Stereocontrolled Synthesis of 3-(trans-2-Aminocyclopropyl)alanine, a Key Component of Belactosin A

Abstract
Herein we report a concise synthesis of 3-(trans-2-aminocyclopropyl)alanine, a component of belactosin A, using asymmetric alkylation of a glycine enolate in the presence of chiral phase-transfer catalysts to control the configuration at C2. Reaction of protected glycidol with triethyl phosphonoacetate (Wadsworth−Emmons cyclopropanation) is used for enantiospecific preparation of an intermediate cyclopropanecarboxylate that is converted to a cyclopropylamine via Curtius rearrangement.