allyl (4R,5S,6S)-3-(((3S,5S)-1-((allyloxy)carbonyl)-5-(1-(methoxyimino)-2-ureidoethyl)pyrrolidin-3-yl)thio)-6-((R)-1-hydroxyethyl)-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate

(2S,4S)-2-[(Imino-piperazin-1-yl-methyl)-carbamoyl]-4-tritylsulfanyl-pyrrolidine-1-carboxylic acid allyl ester

(4R,5S,6S)-3-((3S,5S)-1-Allyloxycarbonyl-5-{1-[(E)-methoxyimino]-2-nitro-ethyl}-pyrrolidin-3-ylsulfanyl)-6-((R)-1-hydroxy-ethyl)-4-methyl-7-oxo-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid allyl ester

(2S,4S)-2-{3-[(E)-Methoxyimino]-pyrrolidine-1-carbonyl}-4-tritylsulfanyl-pyrrolidine-1-carboxylic acid allyl ester

(2S,4S)-2-(3-Oxo-pyrrolidine-1-carbonyl)-4-tritylsulfanyl-pyrrolidine-1-carboxylic acid allyl ester