Asymmetric aza-[2,3]-Wittig sigmatropic rearrangements: chiral auxiliary control and formal asymmetric synthesis of (2S, 3R, 4R)-4-hydroxy-3-methylproline and (–)-kainic acid
作者:James C. Anderson、Julian M. A. O'Loughlin、James A. Tornos
DOI:10.1039/b506198a
日期:——
stereochemistry of aza-[2,3]-Wittig sigmatropic rearrangements with diastereoselectivities of ca. 3 : 1 with respect to the auxiliary. In two specific examples, ca. 50% yields of enantiomerically pure products were obtained after chromatographic purification. These were synthetically manipulated with no erosion of stereochemistry into intermediates that completed formal asymmetric syntheses of (+)-HyMePro
一项对16种不同手性助剂的调查和各种策略发现,甘氨酸衍生的迁移基团的(-)-8-苯基薄荷醇酯可以控制aza- [2,3] -Wittigσ重排的绝对立体化学,并且具有ca的非对映选择性。相对于辅助设备为3:1。在两个具体示例中,色谱纯化后,对映体纯产物的产率为50%。这些在不影响立体化学侵蚀的情况下进行了人工合成,完成了中间体的合成,这些中间体完成了(+)-HyMePro和(-)-海藻酸的形式不对称合成。