Vinylenedionium Salts Containing Different Onium Groups

Vinylenesulfonium-ammonium and vinylenesulfonium-pyridinium salts of type (4) have been synthesized as the first representatives of their class. They react differently from the analogous disulfonium slats. Thus tertiary amines do not substitute either of the two onium groups in (4), RAlkyl, but selectively demethylate the sulfonium group.