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

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