(6R,7R)-3-[(1-methyltetrazol-5-yl)sulfanylmethyl]-8-oxo-7-[[2-(trifluoromethylsulfanyl)acetyl]amino]-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid
(6R,7R)-3-[[(1-methyl-5-tetrazolyl)thio]methyl]-8-oxo-7-[[1-oxo-2-(trifluoromethylthio)ethyl]amino]-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid
(6R,7R)-8-keto-3-[[(1-methyltetrazol-5-yl)thio]methyl]-7-[[2-(trifluoromethylthio)acetyl]amino]-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid
(6R,7R)-3-[(1-methyl-1,2,3,4-tetrazol-5-yl)sulfanylmethyl]-8-oxo-7-[2-(trifluoromethylsulfanyl)ethanoylamino]-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid