The syntheses and the antibacterial activities of new 3-dimethoxyphosphinylmethyl and 3-dihydroxyphosphinylmethyl cephalosporins I-(Z), II-(Z), III-(Z) and III-(E), possessing the chloromethylene or methoxyimino substituent at the α-position to the 7-(2-aminothiazol-4-yl)acetamido or 7-(thiazol-4-yl)acetamido moiety of the cephem nucleus, are described. The key steps of these syntheses were the Michaelis-Arbusov reaction of the 3-halomethylcephem 1 with trimethyl phosphite and the dealkylation reactions of both the dimethoxyphosphinyl group and the p-methoxybenzyl ester of 7a, b-(Z) by treatment with bromotrimethylsilane to afford 9a, b-(Z).
本文介绍了新的 3-二甲氧基膦酰甲基和 3-二羟基膦酰甲基
头孢菌素 I-(Z)、II-(Z)、III-(Z) 和 III-(E)的合成和抗菌活性,它们在
头孢菌素核的 7-(
2-氨基噻唑-4-基)乙酰
氨基或 7-(
噻唑-4-基)乙酰
氨基的 α 位上具有
氯亚甲基或甲氧基亚
氨基取代基。这些合成的关键步骤是 3-卤甲基头孢
环己烷 1 与亚
磷酸三甲酯的 Michaelis-Arbusov 反应,以及 7a, b-(Z)的二甲氧基膦酰基和对甲氧基苄酯经
溴化三甲基
硅烷处理后的脱烷基反应,从而得到 9a, b-(Z)。