(3S,4S)-3-((R)-(1-(tert-butyldimethylsilyl)oxy)ethyl)-4-((3R)-4-oxotetrahydro-4H-thiopyrane-3-yl)azetidine-2-one

allyl (5S,6S,7R)-5-[(R)-1-hydroxyethyl]-4-oxo-9-thia-3-azatricyclo[5.4.0.03,6 ]undec-1-ene-2-carboxylate

allyl (5S,6S,7S)-5-[(R)-1-hydroxyethyl]-4-oxo-9-thia-3-azatricyclo[5.4.0.03,6 ]undec-1-ene-2-carboxylate

(2S,2aS,2bR)-2-((R)-1-Methanesulfonyloxy-ethyl)-1-oxo-2,2a,2b,3,5,6-hexahydro-1H-4-thia-7a-aza-cyclobuta[a]indene-7-carboxylic acid allyl ester