7-(-AMINO(5,6-DIHYDRO-1,4-DITHIN AND 1,4-OXATHIIN-2-YL)ACETAMIDO) CEPHALOSPORANIC AND DESACETOXY CEPHALOSPORANIC ACIDS AND ESTERS, PROCESSES FOR THEIR PREPARATION AND PHARMACEUTICAL COMPOSITIONS CONTAINING THEM

摘要

New cephalosporin compounds of the formula: (I) in which A is oxygen or sulphur, R1 is hydrogen or acetoxy and R2 is carboxy or a radical of the formula: (II) in which the radical (III) is a radical which can be easily removed enzymatically, and in which R3 is hydrogen or straight or branched chain C1-4 alkyl and R4 is straight or branched chain C1-4, alkyl or cyclohexyl, together with its diastereoisomeric forms and mixtures thereof, its acid addition salts and, where appropriate, its pharmaceutically acceptable non-toxic metal salts and addition salts with nitrogen-containing bases other than ammonia, exhibit valuable anti-bacterial properties, in particular against Gram-positive and Gram-negative bacteria.