(5R,6S)-3-(3-Amino-propylsulfanyl)-6-((R)-1-hydroxy-ethyl)-7-oxo-4-thia-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid

(5R,6S)-3-(3-Azido-propylsulfanyl)-6-[(R)-1-(tert-butyl-dimethyl-silanyloxy)-ethyl]-7-oxo-4-thia-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitro-benzyl ester

(5R,6S)-6-((R)-1-Hydroxy-ethyl)-3-(3-hydroxy-propylsulfanyl)-7-oxo-4-thia-1-aza-bicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitro-benzyl ester