Abstract
Dimethylsulfonium 2-oxo-3, 4-diphenyl-3-butenylide derivatives (Ia-c) rearranged in boiling ethanol, in a Pummerer-type fashion, to produce 1, 2-diphenyl-3-methylthiomethoxy-1, 3-butadiene (IVa-c). Nucleophilicity of the ylid (I) was examined by the reactions described below. I-a still reacted with dimethyl acetylenedicarboxylate and ethyl propiolate to afford new stable ylids of dimethylsulfonium 1, 2-dimethoxycarbonyl-4-oxo-5, 6-diphenyl-1, 5-hexadien-3-ylide (IX) and dimethylsulfonium 1-ethoxycarbonyl-4-oxo-5, 6-diphenyl-1, 5-hexadien-3-ylide (X), respectively. I also reacted with phenylisocyanate derivatives forming stable ylids, dimethylsulfonium 1-phenylcarbamoyl-2-oxo-3, 4-diphenyl-3-butenylide derivatives (XIa-e).
