Process for the preparation of cephem derivatives and entermediates therefor

Abstract From the Canadian patent

A cephem derivative represented by the following formula:, (see fig. I), wherein R1 means a fluorine-substituted lower alkyl and A1 denotes a cyclic or acyclic ammonio group or, a non-toxic salt thereof, is prepared by reacting a compound represented by the following formula: (see fig. II), wherein A1 has the same meaning as defined above with another compound represented by the following formula:, (see fig. III), wherein R1 has the same meaning as defined above and, if necessary, removing the protecting groups.