sodium 6β-<(D)-2-(4-ethyl-2,3-dioxopiperazin-1-ylcarbonylamino)-2-(3,4-diacetoxyphenyl)acetamido>-6α-formamidopenicillanate 1α-oxide

benzyl 6β-<(D)-2-(4-ethyl-2,3-dioxopiperazin-1-ylcarbonylamino)-2-(3,4-diacetoxyphenyl)acetamido>-6α-formamidopenicillanate 1α-oxide

benzyl 6β-penicillanate 1β-oxide

benzyl 6β-<-N-(2,2,2-trichloroethoxycarbonyl)-N-trifluoromethylsulphonylamino>penicillanate 1α-oxide

(2S,6S)-6-Methoxy-3,3-dimethyl-7-oxo-6-(2,2,2-trichloro-ethoxycarbonylamino)-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylic acid benzyl ester