Hetero-Diels-Alder reactions of chlorodithioformates with acyclic 1,3-dienes

Abstract

At elevated temperatures chlorodithioformates 1 react with acyclic 1,3-dienes 2 with remarkable regioselectivity to yield 2 H -3,6-dihydrothiopyrans 3 . Spontaneous loss of HCl from 3 leads to the isolable but labile 2 H -thiopyrans 4 .