ADDITION OF ORGANOMETALLICS TO α,β-UNSATURATED THIOCARBONYL COMPOUNDS. III. MICHAEL ADDITION OF ACTIVE METHYLENE COMPOUNDS TO THIOAMIDE AND DITHIOCARBAMATE VINYLOGS

Abstract

α,β-Unsaturated thiocarbonyl compounds substituted by a secondary amino group in position β, such as thioamide and dithiocarbamate vinylogs, react with sodium derivatives of active methylene compounds CH₂XY to give 1,4-addition compounds. Methylation of the 1,4-adducts is followed by elimination of the amine and leads to conjugate thioethers and ketene dithioacetals with functional groups X and Y at the end of the chain. Cyclization and hydrolysis of the adduct afford 2H-thiopyran derivatives.