STEREOSELECTIVE ADDITION OF ARENE THIOLS TO 1,4-DISUBSTITUTED-2-BUTYNES

Abstract
Base-catalyzed addition of arene thiols to 1,4-disubstituted-2-butynes (1 and 2) afford the β,γ-unsaturated sulfones (8E and 8Z). In addition to the regiospecificity observed, the vinyl sulfides are formed with a high degree of stereoselectivity. Product formation through a less-hindered approach by the nucleophile appears to favor the E over the Z isomer, consistently in all the 11 cases investigated.