cyclic sulfone (CAS no ), which is also known as 1,3-, 2-methyl-, sulfone, could be produced through the following synthetic route.

A 600-ml. steel reaction vessel is precooled before loading by filling it between one-fourth and one-half full of methanol (CAS no ) and Dry Ice. After removal of the methanol and Dry Ice, the autoclave is charged with 120 g. (176 ml., 1.76 moles) of isoprene (CAS no ), 113 g. (80 ml., 1.76 moles) of liquid sulfur dioxide, 88 ml. of methanol, and 4 g. of hydroquinone. The vessel is sealed, heated slowly to 85°, and maintained at that temperature for 4 hours. It is then cooled, the sulfone removed, the bomb rinsed with methanol, and the combined product and washings are treated hot with 5 g. of Norite. The filtered solution is concentrated to a volume of 250–300 ml., and the sulfone is allowed to crystallize. The material is filtered and washed with 50 ml. of cold methanol. Recrystallization from methanol (20 ml. per 25 g. of sulfone) yields 140–150 g. of thick, colorless plates. Concentration of the mother liquors raises the total yield to 182–191 g. (78–82%), melting at 63.5–64°.