The Claisen rearrangement of the ketene aminal derived by selenoxide elimination of the seleno-aminal 1 in refluxing toluene in the presence of dihydropyran yields the expected unsaturated eight-membered lactam derivative 3, as well as two unexpected products 7a and 7b; the major product 7a(resulting from a selenium re-addition reaction) was shown by X-ray crystallography to be a highly distorted transoid amide (imide) with the largest p-orbital distortion (τ= 50.6°) recorded for a cyclic amide.
在二氢
吡喃存在下,在回流
甲苯中对通过
硒氧化物消除
硒酰胺 1 得到的酮酰胺进行克莱森重排,得到了预期的不饱和八元内酰胺衍
生物 3 以及两种意想不到的产物 7a 和 7b;X 射线晶体学显示,主要产物 7a(由
硒再加成反应生成)是一种高度畸变的横向酰胺(
酰亚胺),其 p-轨道畸变最大(τ= 50.6°)。