Propanedithiol Bis p-toluenesulfonate

Ashnagar, A. Bruce, J. M. Lloyd-Williams, R, J. Chem. Soc., Perkin Trans. 11988, 559. 

Physical Data 1,3-propanedithiol bis(/)-toluenesulfonate) mp 67°C l,2-ethanedithiolbis(/ toluenesulfonate) mp76°C. Preparative Methods treatment of potassium thiotosylate, itself made by the reaction of / -toluenesulfonyl chloride with potassium hydrogen sulfide, with 1,3-dibromopropane or 1,2-dibromoethane in the presence of potassium iodide affords 1,3-propanedithiol bis(/ -toluenesulfonate) and 1,2-ethanedithiol bis(p-toluenesulfonate), respectively.  

The exquisite regioselectivity possible in enamine formation or a-formylation of cycloalkanones, followed hy a,a-dithianation and ring cleavage, has been exploited in several natural product syntheses (eqs 2-4).  

Addition of organometallics to the carbonyl carbon, followed by base cleavage of the resulting a,a-dithianyl carbinols, generates fw-dithianyl ketones (eq 5).  

Dithianes and dithiolanes can be removed under hydrolytic or reductive conditions. As a,a-dithianyl- and dithiolanylation of ketones effects oxidation of the a-carbon, hydrolytic removal 

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