(3S,4R)-3-<(tert-Butyldiphenylsilyl)oxy>-1-<(2,3-dimethyl-2-butyl)dimethylsilyl>-4-<<4-(benzyloxy)-2-methyl-4-nitro-3(Z)-buten-2-yl>thio>-2-azetidinone

6β-hydroxypenicillanic acid benzyl ester

(2S,5R,6S)-Benzyl 6-Hydroxy-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate

6R(β)-tritylaminopenicillanic acid

methyl 6β-(triphenylmethylamino)penicillinate