(2R)-({[4-((2R,3R)-1-(4-fluorophenyl)-3-{[2-(4-fluorophenyl)-2-oxoethyl]thio}-4-oxoazetidin-2-yl)phenoxy]acetyl}amino)(phenyl)acetic acid

(4-{(2R,3R)-1-(4-fluoro-phenyl)-3-[(RS)-2-(4-fluoro-phenyl)-2-oxoethylsulfanyl]-4-oxo-azetidin-2-yl}-phenoxy)-acetic acid

tert-butyl (4-{(1R)-1-[(4-fluorophenyl)amino]-2-[(4-methoxybenzyl)thio]-3-oxo-3-[(4S)-2-oxo-4-phenyl-1,3-oxazolidin-3-yl]propyl}phenoxy)acetate

(3R,4R)-1-(4-fluorophenyl)-3-[(4-fluorobenzoyl)methylthio]-4-[4-(t-butoxycarbonylmethoxy)phenyl]azetidin-2-one

tert-butyl (4-{[(4-fluorophenyl)imino]methyl}phenoxy)acetate

(3R,4R)-1-(4-fluorophenyl)-3-[(3-nitropyridin-2-yl)dithio]-4-[4-(t-butoxycarbonylmethoxy)phenyl]azetidin-2-one