Asymmetric Synthesis ofα,γ-Substitutedγ-Sultones via Allylation of Chiral Lithiated Sulfonates
作者:Dieter Enders、Wacharee Harnying、Nicola Vignola
DOI:10.1002/ejoc.200300342
日期:2003.10
The first auxiliary controlled asymmetric synthesis of enantiopure α,γ-substituted γ-sultones via α-allylation of lithiated sulfonates by using 1,2:5,6-di-O-isopropylidene-α-D-allofuranose as chiral auxiliary is described. The high asymmetric inductions of the α-allylations were reached in good to excellent yields. Successive epimerization-free cleavage of the auxiliary and diastereoselective ring
描述了使用 1,2:5,6-二-O-异亚丙基-α-D-别呋喃糖作为手性助剂,通过锂化磺酸盐的 α-烯丙基化,控制对映体纯 α,γ-取代 γ-磺内酯的第一个辅助控制不对称合成。α-烯丙基化的高不对称诱导达到了良好至极好的产率。在一锅法中,磺酸中间体的辅助和非对映选择性闭环的连续无差向异构化裂解导致标题化合物的产率良好至极好以及非对映体和对映体过量(de,ee ≥ 98%)。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)