Intramolecular cycloaddition of nitrones and nitrile oxides with sulfur-substituted dienes and its synthetic applications

A series of sulfur-substituted dienyl nitrones and oximes were conveniently prepared from the 3-sulfolene precursors. Regiospecific intramolecular 1,3-dipolar cycloadditions of nitrones and nitrile oxides with sulfur-substituted dienes have been efficiently carried out from the suitable 3-sulfolene precursors. The stereochemistry of the cycloaddition of nitrones depends on the structure of the substituent (sulfide or sulfone) on the diene as well as on the chain length connecting the diene and nitrone. The fused bicyclic products obtained from these reactions have been converted to some interesting heterocyclic compounds which have the useful structure of vinyl sulfide or sulfone.