Acetic acid (R)-7-azido-3-[(2R,3S)-3-((R)-1-hydroxy-ethyl)-4-oxo-azetidin-2-yl]-2-oxo-heptyl ester

(3S,4R)-3-<(1R)-1-triethylsilyloxyethyl>-4-<(1R)-1-(4-tert-butoxycarbonylaminobutyl)-2-oxo-3-acetoxypropyl>-2-azetidinone

benzhydryl (1S,5R,6S)-1-(4-tert-butoxycarbonylaminobutyl)-2-hydroxymethyl-6-<(1R)-1-triethylsilyloxyethyl>carbapen-2-em-3-carboxylate

(3S,4R)-3-<(1R)-1-triethylsilyloxyethyl>-4-<(1R)-1-(4-tert-butoxycarbonylaminobutyl)-2-oxo-3-acetoxypropyl>-1-(diphenylmethoxycarbonyl-hydroxymethyl)-2-azetidinone

benzhydryl (1S,5R,6S)-1-(4-tert-butoxycarbonylaminobutyl)-2-(1,3,4-thiadiazol-2-yl)thiomethyl-6-<(1R)-1-triethylsilyloxyethyl>carbapen-2-em-3-carboxylate