Imino ether cephalosporin derivs - with antibacterial activity

摘要

7, beta-Acylamidoceph-3-em-4-carboxylic acids (I) and their non-toxic derivs., in which the acylamido gp. is: (where R = H or an org. gp. and Ra is an etherified gp. bonded to the O atom via a C atom), the cpd. being in the form of a syn isomer or a mixt. contg. =75%, pref. =90%, syn isomer, have antibacterial activity. Prefd. (I) include Rx-C-CO-Q (where Q is the residue of 1-ACA, and Rx is phenyl, naphthyl, thienyl, furyl, benzothienyl or benzofuryl). Cpds. (I) may be prepd. e.g. reacting an opt. carboxyl-protected M-ACA with an acylating agent derived from RC(NORa)COOH or a precursor.