Regiospecific Vinyl Phosphate/β-Keto Phosphonate Rearrangements Initiated by Halogen−Metal Exchange
作者:Tracy J. Baker、David F. Wiemer
DOI:10.1021/jo972131x
日期:1998.4.1
trapping the resulting enolate by reaction with a dialkyl phosphorochloridate gives the 2-bromovinyl phosphate. Metalation can be accomplished upon treatment with n-BuLi, and rearrangement is facile once metalation has been achieved. Studies with isotopically labeled substrates have shown that this rearrangement is regiospecific, in contrast to vinyl phosphate/beta-keto phosphonate rearrangements induced
已经开发了通过卤素-金属交换诱导2-溴乙烯基磷酸酯的1,3-磷迁移来制备β-酮基膦酸酯的新策略。这些中间体可通过与强碱反应,将α-溴代酮转化为适当的烯醇化物,或通过共轭添加到α-溴代α,β-不饱和酮中来制备。在任一种情况下,通过与磷酰氯二烷基酯反应捕集所得的烯醇化物,得到2-溴乙烯基磷酸酯。金属化可以在用正丁基锂处理时完成,一旦实现金属化,重排就很容易。同位素标记底物的研究表明,这种重排具有区域特异性,