Penem-3-carboxylic acid derivatives of formula (I): ##STR1## (wherein: R.sup.1 represents a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyalkyl group, an acyloxyalkyl group, an alkylsulphonyloxyalkyl group, an arylsulphonyloxyalkyl group or a trialkylsilyloxyalkyl group; R.sup.2 represents a hydrogen atom or an alkyl group; R.sup.3 represents a hydrogen atom, an amino-protecting group or a group of formula ##STR2## in which R.sup.5 and R.sup.6 are the same or different and each represents a hydrogen atom or an alkyl group; A represents a branched-chain alkylene group; and R.sup.4 represents a carboxy group or a protected carboxy group) and pharmaceutically acceptable salts thereof, may be prepared by heating a corresponding phosphorus-ylide compound or by reacting a corresponding azetidin-2-one with a suitable phosphorous acid triester or triamide, and have been found to have excellent antibacterial activity accompanied by a very low acute toxicity.
公式(I)的Penem-3-
羧酸衍
生物:##STR1##(其中:R.sup.1代表氢原子,烷基,烷氧基,羟烷基,酰氧基烷基,烷基
磺酸氧基烷基,芳基
磺酸氧基烷基或三烷基
硅氧基烷基;R.sup.2代表氢原子或烷基;R.sup.3代表氢原子,
氨基保护基或公式##STR2##中的基团,其中R.sup.5和R.sup.6相同或不同,且均代表氢原子或烷基;A代表分支链烷基;R.sup.4代表羧基或受保护的羧基),以及其药学上可接受的盐,可以通过加热相应的膦-
亚胺化合物或将相应的氮杂环
丙酮与适当的
磷酸三酯或三酰胺反应来制备,并且发现它们具有出色的抗菌活性,伴随着非常低的急性毒性。