Synthesis of tetronic acid derivatives from novel active esters of α-hydroxyacids

Abstract

Active esters, produced by condensation of O-acetyl protected α-hydroxyacids with N-hydroxysuccinimide, react with anions of active methylene compounds to afford β,β′-tricarbonyl derivatives which upon deprotection undergo cyclization to 3-alkoxycarbonyl and 3-acyl tetronic acids. Incorporation of (S)-2-acetoxyphenylacetic acid in this reaction sequence enables the synthesis of optically active 5-phenyltetronic acid derivatives.