diphenylmethyl 7β-(phenylacetamido)-7α-methoxy-3-methylene-1-oxadethia-3-cephem-4α-carboxylate

(2R,6R,7R)-7-Benzoylamino-7-methoxy-3-methylene-8-oxo-5-oxa-1-aza-bicyclo[4.2.0]octane-2-carboxylic acid benzhydryl ester

(Z)-3-Methyl-4-oxo-2-((3S,4R)-2-oxo-3-phenylacetylamino-4-p-tolyldisulfanyl-azetidin-1-yl)-but-2-enoic acid benzhydryl ester

(Z)-4-Hydroxy-3-methyl-2-((3S,4R)-2-oxo-3-phenylacetylamino-4-p-tolyldisulfanyl-azetidin-1-yl)-but-2-enoic acid benzhydryl ester

(Z)-2-{(2R,3S)-2-[(2R,3S)-1-((Z)-1-Benzhydryloxycarbonyl-2-methyl-3-oxo-propenyl)-4-oxo-3-phenylacetylamino-azetidin-2-yldisulfanyl]-4-oxo-3-phenylacetylamino-azetidin-1-yl}-3-methyl-4-oxo-but-2-enoic acid benzhydryl ester