(1R,5S,6S)-6-[(1R)-1-hydroxyethyl]-2-[(2S,5S,7S)-2-ethyl-2-methyl-4-oxo-1,3-diazabicyclo[3.3.0]octan-7-ylthio]-1-methylcarbapen-2-em-3-carboxylic acid

(4R,5S,6S)-6-((R)-1-Hydroxy-ethyl)-4-methyl-3-((3R,6S,7aS)-3-methyl-1-oxo-3-propyl-hexahydro-pyrrolo[1,2-c]imidazol-6-ylsulfanyl)-7-oxo-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid

(4R,5S,6S)-6-((R)-1-Hydroxy-ethyl)-4-methyl-3-((3S,6S,7aS)-3-methyl-1-oxo-3-propyl-hexahydro-pyrrolo[1,2-c]imidazol-6-ylsulfanyl)-7-oxo-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid

(4R,5S,6S)-3-[(3S,5S)-5-(2-Carbamoyloxy-ethylsulfanylmethyl)-pyrrolidin-3-ylsulfanyl]-6-((R)-1-hydroxy-ethyl)-4-methyl-7-oxo-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid

4-nitrobenzyl (1R,5S,6S)-6-[(R)-1-hydroxyethyl]-1-methyl-2-[(R)-2(S)-methyl-5-oxopyrrolidin-3-ylthio]-1-carbapen-2-em-3-carboxylate