6β-phenoxyacetylsulfanyl-penicillanic acid 2,2,2-trichloro-ethyl ester
6α-phenoxyacetylsulfanyl-penicillanic acid 2,2,2-trichloro-ethyl ester
3-phenylethanoic dithioperoxyanhydride
allyl (5R,6S)-2-(phenoxyacetylthiomethyl)-6-<(1R)-1-tert-butyldimethylsssilyloxyethyl>-penem-3-carboxylate