The compounds of the formula (I): ##STR1## wherein R.sup.1 is a hydrogen atom, a trityl group or an acyl group as found in known antibacterially active penicillins or cephalosporins; R.sup.2 is a hydrogen atom, a lower alkyl group or an aryl group; R.sup.3 is a hydrogen atom, a lower alkyl group, a substituted lower alkyl or a thiosubstituted lower alkyl group; and R.sup.4 is a group such that CO.sub.2 R.sup.4 is a carboxylic acid group or a salt or readily removable ester thereof; are antibiotics. The compounds may be formulated in pharmaceutical compositions. Processes for the preparation of the compounds (I) are also described.
化学式为(I)的化合物:##STR1##其中R.sup.1是氢原子,三苯甲基基团或在已知的具有抗细菌活性的
青霉素或
头孢菌素中发现的酰基基团;R.sup.2是氢原子,较低的烷基基团或芳基基团;R.sup.3是氢原子,较低的烷基基团,取代的较低烷基或
硫代取代的较低烷基基团;而R.sup.4是一种基团,使得CO.sub.2R.sup.4是
羧酸基团或其盐或易于去除的酯;这些化合物是抗生素。这些化合物可以制成药物组合物。还描述了制备化合物(I)的方法。