1,3-Butadiene, 2-methyl-, sulfone 1193-10-8 3-Methyl-2,5-dihydrothiophene 1,1-dioxide 3-Methyl-2,5-dihydrothiophene dioxide 3-Methyl-3-sulfolene 3-Methylsulfolene NSC15090 Thiophene, 2,5-dihydro-3-methyl-, 1,1-dioxide