Prilezhaev reaction

The reaction is highly stereospecific in the sense that the double bond stereochemistry is generally transferred to the relative configuration of the epoxide with essentially perfect fidelity, so that a trans-olefin leads to the stereoselective formation of the trans-2,3-substituted epoxide only, as illustrated by the example above, while a cis-olefin would only give the cis-epoxide.

[1] The reaction proceeds through what is commonly known as the "butterfly mechanism", first proposed by Bartlett, wherein the peracid is intramolecularly hydrogen-bonded at the transition state.

[5] Although there are frontier orbital interactions in both directions, the peracid is generally viewed as the electrophile and the alkene as the nucleophile.

[6] The "butterfly mechanism" takes place via a transition state geometry in which the plane of the peracid bisects that of the alkene, with the O–O bond aligned perpendicular to it.

[7][8] Using the approach of Anslyn and Dougherty (2006, p. 556), the mechanism can be represented as follows:[9] There is a very large dependence of the reaction rate on the choice of solvent.