Process for preparing 4-acetoxy-3-hydroxyethylazetizin-2-one derivatives.

摘要

A process for preparing 4-acetoxy-3-hydroxyethylazetizin-2-one derivative having the general formula (II): wherein R<1> is a protective group for hydroxy group, which comprises reacting the beta -lactam compound having the general formula (I): wherein R<1> is above, R<2>, R<3> and R<4> are a lower alkyl group of C1 to C4, phenyl group or aralkyl group and R is a protective group for N, with acetic anhydride in the organic solvent in the presence of base and then removing the protective group for N. 4-Acetoxy-3-hydroxyethylazetin-2-one derivatives are the useful intermediates for preparing carbapenem beta -lactam antibiotics such as thienamycin and penem beta -lactam antibiotics.