Formation of α-Disulfoxides, Sulfinic Anhydrides, and Sulfines during the m-Chloroperoxybenzoic Acid Oxidation of Symmetrical S-Alkyl Alkanethiosulfinates

Article abstract of DOI:10.1021/ja00350a049

The m-chloroperoxybenzoic acid (MCPBA) oxidation of S-methyl methanethiosulfinate (33), S-propyl propanethiosulfinate (34), S-2-propyl 2-propanethiosulfinate (35), S-butyl butanethiosulfinate (36), and S-(phenylmethyl)phenylmethanethiosulfinate (37) has been at low temperatures and compared with the MCPBA oxidation of S-(2-methyl-2-propyl)-2-methyl-2-propanethiosulfinate (26) and S-(2,2-dimethylpropyl)-2,2-dimethylpropanethiosulfinate (30).Diastereomeric α-disulfoxides are observed with 33-36 at -40 deg C, sulfinic anhydrides are observed with 33, 35, and 36 at -40 deg C, and sulfines are observed on warming the product mixtures from 34-37 from -40 deg C to -20 deg C.The lachrymatory factor ((Z)-propanethial S-oxide, 47) of the onion was observed during the oxidation of 35.The absence of thiosulfonates at -40 deg C and their presence at higher temperature suggest that they are not formed in the initial oxidation process but from subsequent reactions of thiosulfinates and sulfinic acids.Various mechanisms for the formation of intermediates and products are discussed.