Evidence is presented that the only significant reaction of 2-methyl-2-propanesulfonyl chloride (1)(a) in water over the pH range 3.5-13.0 or (b) in methanol-chloroform-d is an ionization to the tert-butyl cation (2) and the chlorosulfite anion (ClSOZ-), followed by further reactions of these species. The organic products include isobutylene (31, tert-butyl chloride (4a), tert-butyl alcohol (4b), and, at high pH, 2-methyl-2-propanesulfinate anion (6) and ...