Compounds of the formula: ##STR1## wherein R.sub.1 is hydrogen, alkyl(C.sub.1 -C.sub.3), vinyl, acetyloxy or ##STR2## wherein R.sub.3 is hydrogen or alkyl(C.sub.1 -C.sub.6); R.sub.2 is hydrogen or diphenylmethyl and A is R.sub.4 --C, where R.sub.4 is acetyl or benzoyl, are useful as intermediates in the preparation of biologically active cephalosporin derivatives.
分子式为##STR1##其中R.sub.1为氢、烷基(C.sub.1-C.sub.3)、
乙烯基、乙酰氧或##STR2##其中R.sub.3为氢或烷基(C.sub.1-C.sub.6);R.sub.2为氢或二苯甲基,A为R.sub.4--C,其中R.sub.4为乙酰或苯甲酰,可用作制备
生物活性
头孢菌素衍
生物的中间体。