Highly diastereoselective synthesis of substituted epichlorohydrins and regioselective preparation of allyl alcohols using chloro or iodomethyllithium
作者:JoséM. Concellón、Luján Llavona、Pablo L. Bernad
DOI:10.1016/0040-4020(95)90943-q
日期:1995.5
Substituted epichlorohydrins 3 or 6 are obtained from α-bromo or α-chlorocarbonyl compounds (1 or 4) and chloro or iodomethyllithium, respectively. Starting from α-bromocarbonyl compounds 1 or acyclic α-chloro ketones the reaction takes place with total diastereoselectivity. Treatment of epichlorohydrins 3 or 6 with lithium iodide affords the same substituted allyl alcohols 7 in a regioselective manner
取代的表氯醇3或6分别从α-溴或α-氯羰基化合物(1或4)和氯或碘甲基锂获得。从α-溴羰基化合物1或无环α-氯代酮开始,反应以完全非对映选择性进行。用碘化锂处理表氯醇3或6以区域选择性的方式提供相同的取代的烯丙醇7。提出了一种解释这种转变的机制。区域异构的烯丙醇11是通过表氯醇6与锂粉反应制备的。