A Formal Total Synthesis of Thienamycin from 4-Propargyl-2-azetidinone

Abstract

A mild and efficient method for the conversion of propiolic esters to β-keto esters was developed. Initially, propiolic esters were converted to β-phenylthio-α, β-unsaturated esters, which were treated with N-bromoacetamide in an aqueous solvent followed by reductive debromination with an aqueous solution of sodium sulfite, affording β-keto esters in good yields. Using this new method, a formal total synthesis of (±)-thienamycin from 4-propargyl-2-azetidinone was accomplished.