Reactions of Enolates with Vinyl Selenoxides and Vinyl Selenones. One-step Synthesis of Cyclopropylcarbonyl Compounds

Abstract In the reactions with enolate anions, organoselenium moieties of aryl vinyl selenoxides and selenones have exhibited two important roles, e.g., activation of C=C bonds for conjugate addition reaction and behaviors as excellent leaving groups. Owing to such characteristic features, ketone enolates react with p-chlorophenyl vinyl selenoxide to afford the corresponding cyclopropyl ketones through an initial conjugate addition followed by substitution processes. On the other hand, use of vinyl selenones usually gives much better results with anionic species of active methylene compounds. Vinyl selenones bearing hydroxyl, ketone, and ester groups can also be employed equally well for this type of transformation.