| 摘要 |
PURPOSE:Penicillins and cephalosporins of formula I(R<1> is H, carboxyl protective group, salt-forming cation; Z is radical of formula II or III ;R is amino acid radical ; n is 1, 2, 2;X is O, S;m is 4-n;R<2> ,R<3> are H, halogen, alkyl, cycloalkyl, aryl, acyl;R<4> is H, CN, azide;A is H, CN, alkyl;Y is O, S)9 For example, D(-)alpha-(4-ethyl-2,3-dioxo-piperazinocarbonylamino) benzylpenicillin. |
