2,4,8,10-Tetraoxa-3λ4,9λ4-dithiaspiro[5.5]undecane-3,9-dione3670-93-7100 % similar Ethylene sulfite3741-38-650 % similar 2-Oxo-1,3,2-dioxathiane4176-55-045 % similar Diethyl sulfite623-81-443 % similar