Results The reactions of the adducts 3 and 4 in sulfur dioxide were followed by'H NMR spectroscopy. In agreement with expectation, vinyl chloride 4 ionizes to l-methyl-2, 3-di-tert- butylthiirenium chloride (6) at a measurable rate at room temperature (tl at 25" CN 90 min). The conversion of alkyl chloride d to pentamethylthiiranium chloride 5 is much faster and was to be followed at lower temperature (tllz at-60" CN 5 min). The signals of thiiranium ...
