New cephalosporin comprising a core 2 - cephem, their process of preparation, their application as medicinal products, and the new # obtained.

摘要

Products of general formula (I): IMAGE syn isomer, in the R or S form or of an R, S mixture, in which formula: R1 represents either a heterocyclic radical, or a -S-Het radical, X represents a single bond or a C=C radical in the E or Z form, Rb and Rc represent a hydrogen atom or an acyl group, A and A' represent a hydrogen atom, one equivalent of base, or the residue of an ester group which is easily cleaved or CO2A represents CO2- and the salts of the products of formula (I) with inorganic or organic acids. These products have advantageous properties which justify their use in antibiotherapy.