1, 6-Asymmetric Induction by Reductive Acetal Cleavage of a Bicyclic Acetal Using a Sulfinyl Chiral Auxiliary

Abstract

A new synthetic route to a chiral 2, 5-disubstituted tetrahydropyran has been achieved by asymmetric reductive acetal cleavage of a bicyclic acetal having a chiral sulfinyl group as a chiral auxiliary. It was found that the (5S)-tetrahydropyran was obtained preferentially (up to 96 : 4) with an R-sulfinyl chiral auxiliary by an efficient 1, 6-asymmetric induction from sulfinyl chirality to the prochiral center on the bicyclic ring.