Diaminosulfoxonium salts were prepared by alkylation of sulfonimidamides. Their physical properties were described. Their reaction with bases gave the corresponding ylides and sulfonimidamides. The intramolecular rearrangement of the ylides led to ortho substitution via intermediate cyclohexadienimines. Hydrogen transfer, accompanying rearomatization and the subsequent action of bases gave dihydro-2,1-benzisothiazole derivatives. These ylides were also found to react with aldehydes to afford epoxides in moderate yields.