GENERATION AND [2+3] CYCLOADDITIONS OF A SULFONYLATED THIOCARBONYL S-METHANIDE

摘要

The sulfonylated thiocarbonyl S-methanide (2a) was generated in situ by addition of diazomethane to the C-sulfonylated dithioformate (1a) and subsequent thermal elimination of nitrogen.This 1,3-dipole was intercepted by C,C- and C,S-dipolarophiles.Whereas in the first case the cycloadducts (10) and (11) could be isolated as stable products,the cycloadducts of type (8),which are the proposed products of the reaction with thioketones,underwent a spontaneous rearrangement to give open-chain ketene dithioacetals (5) and (6).