(6R)-3-carbamoyloxymethyl-7c-methoxy-8-oxo-7t-(2-thiophen-2-yl-acetylamino)-(6rH)-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid benzhydryl ester

cephamycin C

(6R)-7t-[(R)-5-benzhydryloxycarbonyl-5-(2,2,2-trichloro-ethoxycarbonylamino)-pentanoylamino]-3-carbamoyloxymethyl-7c-methoxy-8-oxo-(6rH)-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid benzhydryl ester

diphenylmethyl (6R,7S)-7-carboxycarbonylamino-7-methoxy-3-carbamoyloxymethyl-3-cephem-4-carboxylate

2-(((6R,7S)-2-((benzhydryloxy)carbonyl)-3-((((carboxycarbonyl)carbamoyl)oxy)methyl)-7-methoxy-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-en-7-yl)amino)-2-oxoacetic acid