3-chloro-8-oxo-7-phenylacetylamino-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid 4-methoxybenzyl ester
2-((2R,3R)-2-Benzenesulfonylsulfanyl-4-oxo-3-phenylacetylamino-azetidin-1-yl)-buta-2,3-dienoic acid 4-methoxy-benzyl ester
3-methylene-7-oxo-6-phenylacetylamino-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylic acid 4-methoxybenzyl ester
(7R)-7-[(phenylacetyl)amino]-3-trifluoromethanesulfonyloxy-3-cephem-4-carboxylate, 4-methoxybenzyl ester
p-methoxybenzyl (E)-3,4-dichloro-2-<2-oxo-3-(phenylacetamido)-4-<(phenylsulfonyl)thio>azetidin-1-yl>-2-butenoate