3-Carbamyloxymethyl-cephalosporins

The compound of the formula ##STR28## wherein R.sup.o represents hydrogen or R.sup.1, and R.sup.1 represents alkyl of C.sub.1 -C.sub.6, 2,2,2-trichloroethyl, 2-iodoethyl, tert-alkenyl of C.sub.5 -C.sub.7, tert-alkynyl of C.sub.5 -C.sub.7, benzyl, nitrobenzyl, tetrahydropyranyl, succinimidomethyl, phthalimidomethyl, methoxybenzyl, dimethoxybenzyl, cyanomethyl, nitrophenyl, dinitrophenyl, 2,4,6-trinitrophenyl, bis(p-methoxyphenyl)methyl, triphenylmethyl, diphenylmethyl, benzyloxymethyl, loweralkanoyloxymethyl of C.sub.3 -C.sub.6, loweralkanoyl of C.sub.2 -C.sub.4, phenacyl, or radical of the formula ##STR29## wherein each R.sup.2 independently represents loweralkyl of C.sub.1 -C.sub.4 or halo selected from the group consisting of bromo, chloro, fluoro, and iodo, subject to the limitation that at least one R.sup.2 represents loweralkyl as defined;

• and R.sup.3 represents amino or an acylamido group where the acyl group is:
• alkanoyl of C.sub.1 -C.sub.4,
• aroyl of C.sub.6 -C.sub.12,
• alkoxycarbonyl of C.sub.1 -C.sub.4,
• benzyloxycarbonyl,
• cycloalkoxycarbonyl of C.sub.5 -C.sub.6,
• aryloxycarbonyl of C.sub.6 -C.sub.12,
• one of the above groups substituted with from one to three groups, each selected from the group consisting of halo, nitro, loweralkoxy of C.sub.1 -C.sub.4, cyano, and, in the instance of aroyl and aryloxy, by loweralkyl of C.sub.1 -C.sub.4, or phthaloyl, subject to the limitation that at least one of the following exists:
• (1) R.sup.o represents R.sup.1 ;
• or (2) R.sup.3 represents acylamido as defined.