Lithiated 3-Tosylpropanal and 4-Tosyl-2-butanone Dimethyl Acetals as β-Acylvinyl Anion Equivalents for the Synthesis of Unsaturated 1,4-Dicarbonyl Compound and α,β-Butenolides

Article abstract of DOI:10.1016/0040-4020(95)00026-5

The lithiation of 1,1-dimethoxy-3-tosyllpropane (7a) and 2,2-dimethoxy-4-tosylbutane (7b) followed by reaction with acyl chlorides affords, after p-toluenesulfinic acid elimination, ene-1,4-dicarbonyl compounds in a stereoselective manner.In the case of compound 7a, derived from acrolein, sequential monolithiation and reaction with carbonyl compounds give cyclic acetals, which after oxidation and elimination of p-toluenesulfinic acid are transformed into α,β-butenolides.