PROCESS FOR PREPARING ALKENYL CEPHALOSPORIN

摘要

Pyridonium alkenyl cephalosporin derivs. of formula (I) and their pharmaceutical salts are new. 3-Cephem compds. were obtained by witting reaction from a phosphonium cpd. of formula (II) with an aldehyde cpd. of formula (III) and then were deacylated to produce 7-amino-3-cephem derivs. The formula (I) derivs. are prepd. by acylation of 7-amino-3-cephem derivs. with 2- aminothiazolyl- 2-hydroxyimino-acetic acid compds. In (I), R1=H or a protecting gp. as in cephalosporin and penicillin cpds.; R2=H, C1-4 alkyl or substd. alkyl; R3=H or a deriv. of a carboxy gp., an atom for prepn. of a salt or carboxy protecting gp.