Reactions of α-Amino Acid Derivatives with Thionyl Chloride. An Application to a Synthesis of 7α-Methoxycephalosporins

Abstract

Treatment of the α-amino acid ester (IV) and the 7-amino-cephalosporin (VIII) with thionyl chloride and triethylamine afforded the sulfenimines (V) and (IX), respectively. 7β-Amino-7α-methoxy-cephalosporin derivative (XVI) was obtained by methoxylation of the sulfenimine (IXb) with methanol in the presence of triethylamine.