α-allylated chiral thioxanones: Diastereoselective preparation by an S-alkylation/[2,3]-sigmatropic rearrangement sequence.
摘要:
Diastereoselective S-allylation of thioxanone 6 and subsequent ylid formation/[2,3]-sigmatropic rearrangement delivers excellent C-alpha-induction. Non-stereospecific C-beta-induction results from scrambling of olefin geometry in the S-allylation step.
A thioxanone-based chiral template: asymmetric induction in the [2,3]-sigmatropic rearrangement of sulfur ylides. Enantioselective preparation of C.beta.-chiral pent-4-enoic acids
作者:Mark J. Kurth、S. Hasan Tahir、Marilyn M. Olmstead