method for preparation of medicines and methods for preparation of new cephalosporin derivatives.

摘要

7-Acylamino and 7-amino-3-carboxy-3-cephem-4-carboxylic acids and derivatives thereof, which are useful as antibiotics or as intermediates in preparing antibiotic substances, are prepared by an NBS oxidation of acetal derivatives of 3-formyl cephalosporins.