2-Alkoxy-3-cephem-1-oxides 1b-c were found to be thermally unstable and easily converted into isothiazolones 5a-f, β-lactam 12 and thiazole 14 according to reaction conditions. Further, 2-alkoxy-3-cephem 4a-b was treated with tert-butyl hypochlorite to give azetidinone-oxazoline acetals 18a-b. Formation of these rearrangement products was interpreted via the sulfenic acid intermediate 6 or 17.
发现 2-烷氧基-3-头孢-1-氧化物 1b-c 热不稳定,根据反应条件很容易转化为
异噻唑酮 5a-f、β-内酰胺 12 和
噻唑 14。此外,用
次氯酸叔丁酯处理 2-烷氧基-3-头孢 4a-b,可得到氮杂
环丁酮噁唑啉
缩醛 18a-b。这些重排产物是通过亚
磺酸中间体 6 或 17 形成的。