27529-59-5 3,4-Dimethoxysulfolane 3,4-Dimethoxytetrahydrothiophene 1,1-dioxide Tetrahydro-3,4-dimethoxythiophene 1,1-dioxide Thiophene, 3,4-dimethoxytetrahydro-, 1,1-dioxide Thiophene, tetrahydro-3,4-dimethoxy-, 1,1-dioxide