Asymmetric Synthesis of α,γ‐Substituted γ‐Sultones via Allylation of Chiral Lithiated Sulfonates

Abstract

Abstract 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 closure of the sulfonic acid intermediates in a one‐pot procedure led to the title compounds in good to excellent yields and diastereo‐ and enantiomeric excesses ( de , ee ≥ 98%). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)