Prepn of 3-methyl cephalosporins - from 3-acetoxy methyl derivatives by amalgam or stannous reduction

摘要

3-Methyl cephalosporins (I): (where R = H or an acyl gp. which may opt. be substd.) are prepd. by the redn. using aluminium amalgam, zinc amalgam or magnesium amalgam, or a stannous deriv. of an ester of formula (II): The prod. is purified by extracn. recrystallisation or chromatography. The process is simpler to carry out than known prepn methods.