Sulphoxylates rearrangement

Sometimes it is convenient to synthesise an activated alcohol that can be used in nucleophic substitution reactions like an alkyl halide. Mesylates and tosylates are such sulphonate compounds which serve this purpose. They can be synthesised by action of alcohols with sulphoxyl chlorides in the presence of a base like pyridine or triethylamine (Following fig.). The base serves to mop up the HC1 that is formed and avoids acid-catalysed rearrangement reactions. 

Allylic sulphenic acids are transient intermediates in the rearrangement of episulphoxides carrying a suitably located H atom /ru/i5-but-2-ene episulphoxide gives diallyl thiolsulphinate via HaC=CH CHMeSOH, the product (145) existing in equilibrium with the butenyl thio-sulphoxylate (146). 

Allylic sulphones are available through the reaction of a t-butyl sulphoxide and an allyl alcohol with A -chlorosucdnimide, and through the reaction of an allyl alcohol with di(AT-phthalimido) sulphide or di(iV-imidazolyl) sulphide to give a sulphoxylate, e.g. CHa=CHCH20S0CH2CH=CH2, which rearranges to the bis(allyl) sulphone by way of the sulphinate. Further study of the rearrangement of iV-aryl arenesulphonamides to iV-(u-aminoaryl) aryl sulphones has been described. ... 

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