Regioselective synthesis of novel ketene dithioacetals

A series of novel ketene dithioacetals has been synthesized by condensation of active methylene compounds with carbon disulfide in the presence of dialkyl acetylenedicarboxylates. This regioselective reaction provides products in good yield by a Michael addition reaction followed by 5-endo-trig intramolecular cyclization. Structures of synthesized compounds have been characterized by elemental analysis, FT-IR, H-1 NMR, (CNMR)-C-13, and mass spectra. The crystal structure of compound (C17H22O6S2) has been determined. [GRAPHICS] .