Addition of lithiated methoxyallene 2 to imines provided the expected allenyl amines in good yield. These could be cyclized with base or with silver nitrate to a variety of 2,5-dihydropyrrole derivatives. Selected examples describe their conversion to pyrrolidin-3-ones or 3-methoxypyrroles. Most importantly, this [3 + 2]cyclization method could also be applied to the synthesis of 2,5-disubstituted derivatives such as 26-28 and also to the preparation of the enantiopure compound 23.
将石
碳酸化甲氧基烯 2 加入
亚胺中,就能以良好的收率得到预期的异烯胺。这些胺可以用碱或
硝酸银环化成各种 2,5-二氢
吡咯衍
生物。部分实例描述了它们转化为
吡咯烷-3-酮或 3-甲氧基
吡咯的过程。最重要的是,这种[3 + 2]环化方法还可用于合成 2,5-二取代衍
生物,如 26-28 以及制备不纯化合物 23。