New 3-vinylcephalosporin derivatives of the general formula: ##STR1## in the form of a bicyclooct-2-ene or bicyclooct-3-ene, in which formula R.sub.5.sup.a and R.sub.5.sup.b are hydrogen atoms or alkyl radicals, or together form an alkyl radical containing 2 or 3 carbon atoms, R.sub.5.sup.c is an acid-protecting radical, R.sub.1 is an amino-protecting radical, R.sub.2 is an acid-protecting radical or a radical which can be removed by an enzymatic method, and R.sub.3 and R.sub.4, which are identical or different, represent alkyl (optionally substituted by hydroxyl, alkoxy, amino, alkylamino or dialkylamino) or phenyl, or together form, with the nitrogen atom, a saturated heterocyclic ring of 5 or 6 members, optionally containing another hetero-atom, their E and Z forms, and their syn and anti forms, and mixtures thereof, and also their preparation. These new compounds are useful as intermediates for the preparation of biologically active cephalosporins.
新的3-
乙烯基头孢菌素衍
生物的一般式为:##STR1## 以双
环辛二烯或双环辛
三烯的形式存在,其中式中R.sub.5.sup.a和R.sub.5.sup.b为氢原子或烷基基团,或者结合形成含有2或3个碳原子的烷基基团,R.sub.5.sup.c为酸保护基,R.sub.1为
氨基保护基,R.sub.2为酸保护基或可被酶法去除的基团,R.sub.3和R.sub.4相同或不同,代表烷基(可选用羟基、烷氧基、
氨基、烷基
氨基或二烷基
氨基进行取代)或苯基,或者与氮原子结合形成含有5或6个成员的饱和杂环环,可选含有另一个杂原子,其E和Z形式,以及它们的同步和反向形式,以及它们的混合物,以及它们的制备方法。这些新化合物可用作
生物活性
头孢菌素的中间体。