. "(4R,5S,6S)-3-{(3S,5R)-5-[4-((R)-1-Amino-2-carbamoyl-ethyl)-phenyl]-pyrrolidin-3-ylsulfanyl}-6-((R)-1-hydroxy-ethyl)-4-methyl-7-oxo-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid" . "3b" . . . . . . . . . . .