Synthesis of enantiomerically pure 2,5-disubstituted tetrahydrofurans using readily prepared (2S)-1-phenylsulphonylalkan-2-ols

Abstract

Enantiomerically pure (2S)-1-phenylsulphonylalkan-2-ols [S—(1)] have been prepared from 1-chloro3-phenylsulphonylpropan-2-one (2) by the following successive procedures: reduction with baker's yeast, epoxidation with silver(I) oxide, and alkylation with a Grignard reagent. Alkylation of dianions of S—(1), followed by phenylselenocyclization gave enantiomerically pure 2,5-disubstituted tetrahydrofurans [S-(8)] with high regioselectivity.