1,1-dioxo-tetrahydro-1λ6-thiopyran-4,4-dicarboxylic acid

methyl 1,1-dioxothiane-4-carboxylate

二乙烯基砜

米氏酸

3,3-dimethyl-9,9-dioxo-2,4-dioxa-9λ⁶-thiaspiro[5.5]undecane-1,5-dione