diphenylmethyl 7β-amino-7α-formamido-3-<(1-methyl-1H-tetrazol-5-yl)thiomethyl>ceph-3-em-4-carboxylate

Acetic acid 2-acetoxy-5-{(R)-chlorocarbonyl-[(4-ethyl-2,3-dioxo-piperazine-1-carbonyl)-amino]-methyl}-phenyl ester

t-butyl 7α-formamido-7β-<(4-nitrobenzyloxy)carbonylamino>cephalosporanate

diphenylmethyl 7α-formamido-3-<(1-methyl-1H-tetrazol-5-yl)thiomethyl>-7β-<(4-nitrobenzyloxy)carbonylamino>ceph-3-em-4-carboxylate