Photolyses of Alkyl Sulfinates and Sulfites

Methyl, ethyl, n-butyl, n-octyl, benzyl, and allyl p-toluenesulfinates were photolyzed in n-hexane or without solvent. The products analyses indicate that the photolyses of these esters involve the fission of ArSO–OR bond, producing a sulfinyl radical and an alkoxy radical. In the case of the allyl ester, isomerization to the corresponding sulfone took place to some extent. When optically active l-menthyl l-p toluenesulfinate was irradiated, its optical activity decreased fairly quickly while very little photolysis was observed. This photo-racemization was ascribed to the reversible formation of sulfinyl radical and menthyloxy radical. When di-n-butyl sulfite was photolyzed, the products found were explained by assuming the initial formation of n-butoxysulfinyl radical and n-butoxy radical. When n-butyl chlorosulfite was photolyzed, the products found indicate the initial fission of the S–Cl bond instead of the S–O bond.