3-Formylmethyl-cephalosporins

摘要

The invention provides new cephalosporins of the general formula: <IMAGE> (I) in which n=0 or 1, R4 is an amine-protecting radical, Ra5 and Rb5, which are identical or different, are hydrogen atoms or alkyl radicals, or form an alkylene radical of 2 or 3 carbon atoms, Rc5 is a hydrogen atom or an acid-protecting radical and R2 is an acid-protecting radical or a radical which can easily be removed by an enzymatic method. The compounds of formula (I) are in the form of a 3-oxoethyl-bicyclooct-2-ene or -bicyclooct-3-ene or a 3-oxoethylidenebicyclooctane if n=0, and in the form of a 3-oxoethylbicyclooct-2-ene or a 3-oxoethylidenebicyclooctane if n=1. They are useful as intermediates for the preparation of pharmaceutically active cephalosporins.