New cephalosporin compounds of the formula: ##STR1## wherein R.sub.1 is hydrogen or hydroxy, R.sub.2 is a substituted alkanoyl group, R.sub.3 is hydrogen, carbamoyloxy, alkanoyloxy or a heterocyclic-thio group which may have suitable substituents, and R.sub.4 is carboxy or protected carboxy.
新的
头孢菌素化合物的
化学式为:##STR1## 其中 R.sub.1 是氢或羟基,R.sub.2 是取代的烷酰基团,R.sub.3 是氢、
氨基甲酰氧基、烷酰氧基或具有适当取代基的杂环
硫基团,而 R.sub.4 是羧基或保护羧基。