General Route to Racemic and Enantiomeric Carbo- and Heterocyclic Vinyl Sulfoxides via Tandem Michael Addition/Horner Olefination of α-Phosphorylvinyl Sulfoxides^†

A new one-pot synthesis of heterocyclic and carbocyclic vinyl sulfoxides has been developed which involves reaction of α-phosphorylvinyl sulfoxides with carbonyl compounds bearing oxygen, nitrogen, and carbon nucleophilic centers. Use of optically active α-phosphorylvinyl p-tolyl sulfoxides in this tandem Michael addition/Horner olefination reaction leads to the corresponding optically active cyclic sulfoxides. In this way, a variety of optically active chromene, pyrrolizine, chinoline, and cyclopentene sulfoxides have been efficiently prepared.