(6R)-3-(1-methyl-1H-tetrazol-5-ylsulfanylmethyl)-5t,8-dioxo-7t-(2-phenyl-acetylamino)-(6rH)-5λ4-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid 2,2,2-trichloro-ethyl ester
(6R,7R)-3-((1-methyl-1H-tetrazol-5-ylthio)methyl)-8-oxo-7-(2-phenylacetamido)-5-thia-1-aza-bicyclo [4.2.0]oct-2-ene-2-carboxylic acid
(6R)-4c-methylsulfanyl-3-(1-methyl-1H-tetrazol-5-ylsulfanylmethyl)-5t,8-dioxo-7t-(2-phenyl-acetylamino)-(6rH)-5λ4-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid 2,2,2-trichloro-ethyl ester