(-)-Frontalin的形式合成

Formal Synthesis of (-)-Frontalin

(-)-Frontalin是用于手性叔醇构筑测试的基准分子之一.以本实验室发展的[2,3]-Meisenheimer重排为关键反应,以L-天冬氨酸衍生物为起始原料,经Wittig反应、酯基还原、二醇双乙酰化、[2,3]-Meisenheimer重排等7步反应,实现了(-)-Frontalin关键中间体的合成,总收率为34%,ee值为94%.论文工作将[2,3]-Meisenheimer重排构筑手性叔醇的底物范围,从α,β-不饱和酯基的共轭烯烃扩展至孤立烯烃,充分证明了用[2,3]-Meisenheimer重排构筑手性叔醇更加一般的特征.

（-）-Frontalin is usually used as one of standard molecules to test the usefulness of chiral tertiary alcohol construction. Based on methodology of chiral tertiary alcohols construction via [2,3]-Meisenheimer rearrangement which has been developing on our laboratory, the formal synthesis of （-）-frontalin is finished via successive Wittig reaction, ester reduction, [2,3]-Meisenheimer rearrangement, and etc. The total yield is 34% and the ee value is 94%. The substrate scope is expanded from α,β-conjugated olefins into isolated olefins. This proves the more general characteristic of chiral tertiary alcohol construction via [2,3]-Meisenheimer rearrangement.