Alkoxysulfonium salts hydroxy

An alternative method for the formation of aldehydes or ketones makes use of the complexes formed from a methyl sulfide with chlorine or A-chlorosuccinimide (NCS), in what is called the Corey-Kim oxidation. With dimethyl sulfide the salt 28 is generated and reacts with the alcohol to give the alkoxysulfonium salts and hence, on treatment with a base, the carbonyl compound. This reaction has fovmd particular application in the oxidation of 1,2-diols in which one alcohol is tertiary, to give a-hydroxy-aldehydes or ketones without rupture of the carbon-carbon bond. For example, the aldehyde 32 is formed in good yield from the diol 31 using dimethyl sulfide and NCS followed by addition of triethylamine (6.29). This transformation is thought to depend on the preferential five-membered transition... 

Trinitrobenzenesulfonic acid Stereospecific formation of glycols from oxido compds. via l-hydroxy-2-(alkoxysulfonium) salts... 

A soln. of cw-9,10-epoxystearic acid in benzene added dropwise with stirring during 10 min. to a soln. of 2,4,6-trinitrobenzenesulfonic acid in anhydrous dimethyl sulfoxide, stirring continued 15 min., stirred into excess cold ether-ethyl acetate (2 1), the solvent layer decanted, and the oily lower layer stirred 12-14 hrs. with water /hreo-9,10-dihydroxystearic acid. Y 65-70%. Also erythro- from trans-isomer, and prepn. of f. l-hydroxy-2-(alkoxysulfonium) salts, s. M. A. Khud-dus and D. Swern, Tetrah. Let. 1971, 411. 

Hydroxy- and Alkoxysulfonium Ions. In addition to the well-documented formation of the S02-SbFs complex in a mixture of the two components,227 Minkwitz and co-workers228 have recently detected the formation of the fluorodihydroxysulfonium cation 83 [Eq. (4.61)]. Crystal structure analysis of the isolated salt showed bond distances typical of S—O single bonds (1.537 and 1.522 A) and S—F single bonds (1.547 A). The steric demand of the lone electron pair of sulfur results in the compression of bond angles from the ideal tetrahedral arrangement... 

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