The MislowâÂÂEvans rearrangement is a name reaction in organic chemistry. It is named after Kurt Mislow who reported the prototypical reaction in 1966, and David A. Evans who published further developments.
The reaction allows the formation of allylic alcohols from allylic sulfoxides by a 2,3-sigmatropic rearrangement. The conversion can be highly diastereoselective as the chirality at sulphur atom can be transmitted to the carbon next to the oxygen in the product.
The sulfoxide 1 reagent can be generated easily and enantioselectively from the corresponding sulfide by an oxidation reaction. In this reaction various organic groups can be used, R<sup>1</sup> = alkyl, allyl and R<sup>2</sup> = alkyl, aryl or benzyl
A proposed mechanism is shown below:
The mechanism starts with an allylic sulfoxide 1 which undergoes a thermal 2,3-sigmatropic rearrangement to give a sulfenate ester 2. This can be cleaved using a thiophile, such as phosphite ester, which leaves the allylic alcohol 3 as the product.
The reaction has general application in the preparation of trans-allylic alcohols. Douglass Taber used the MislowâÂÂEvans rearrangement in the synthesis of the hormone prostaglandin E2.