2,5-Dichloro-4-methoxycarbonylmethylsulfanyl-benzoic acid tert-butyl ester

(E)-3-(4-Carboxymethylsulfanyl-2,5-dichloro-phenyl)-acrylic acid tert-butyl ester

(2,5-Dichloro-4-methoxycarbonylmethylsulfanyl-benzoylamino)-acetic acid tert-butyl ester

2-({4-[(1E)-2-{[2-(tert-butoxy)-2-oxoethyl]carbamoyl}eth-1-en-1-yl]-2,5-dichlorophenyl}sulfanyl)acetic acid

(6R,7R)-7-[2-(4-Carboxy-2,5-dichloro-phenylsulfanyl)-acetylamino]-3-chloromethyl-8-oxo-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid