作者:Meng-Yang Chang、Chung-Yu Tsai、Ming-Hao Wu
DOI:10.1016/j.tet.2013.05.110
日期:2013.8
An efficient and straightforward three-step synthetic route toward 2,4-disubstituted-3-bromooxetanes 5 with the trans–trans contiguous stereogenic centers is developed from functionalized chalcones 3 via NaBH4-mediated reduction of chalcones 3, followed by NBS-mediated electrophilic cyclization of the resulting trans-cinnamic alcohols 4 in good yield. Skeleton 3 is prepared by Claisen–Schmidt condensation
通过NaBH 4介导的查耳酮3还原反应,再由NBS介导的亲电反应,从功能化的查耳酮3中开发出一种有效,直接的三步合成路线,以2,4-二取代-3-溴氧杂环丁烷5为反式-反式连续立体中心。以高收率将所得反式肉桂醇4环化。骨架3是通过Claisen-Schmidt缩合取代的芳基醛1和芳基甲基酮或叔丁基甲基酮2制备的。合成路线获得了高收率,并且整个反应过程仅花费了一天。研究了骨架3的取代作用,各种反应条件和合理的机理。