Enantioselective total syntheses of (−)-clasto-lactacystin β-lactone and 7-epi-(−)-clasto-lactacystin β-lactone

Abstract

An alkylidene carbene 1,5-CH insertion has been used as a key step in an efficient enantioselective total synthesis of (-)-clasto-lactacystin beta-lactone, and its C7-epimer. An additional noteworthy feature of the synthesis is the use of a novel oxidative deprotection procedure, utilizing DMDO, for the conversion of a late-stage benzylidene acetal into a primary alcohol and a secondary benzoate ester.