Preparation and Reactions of Benzofurano-, Indolo-, and Benzothieno-3-sulfolenes

Benzofurano-, N-tosylindolo-, and benzothieno-3-sulfolenes have been prepared efficiently via their dihydro analogues. These fused 3-sulfolenes serve as ideal precursors for the corresponding heteroaromatic o-quinodimethanes. Derivatives of these 3-sulfolenes bearing bromo or alkyl group substitution from which substituted heteroaromatic o-quinodimethanes are generated have also been synthesized.