A Three-Component Reaction of Alkenyl Thianthrenium Salts, Cyclopropanols and Sulfur Dioxide.

A three-component reaction of alkenyl thianthrenium salts, cyclopropan-1-ols and DABCO·(SO2)2 under catalyst- and additive-free conditions, is accomplished. This sulfonylation with the insertion of sulfur dioxide works efficiently under very mild conditions, leading to a wide range of 1-substituted vinyl sulfones in moderate to good yields. In this protocol, the scope generality of alkenyl thianthrenium salts and cyclopropyl alcohols is demonstrated.