Alkenes react with peracids (peroxyacids) to form epoxides. Epoxides are three-membered cycles that contain oxygen.

epoxidación de alquenos
The most common reagent in this reaction is peroxyacetic acid, although MCPBA can also be used. The most commonly used solvents are dichloromethane and chloroform.
The epoxidation of alkenes is chemoselective, reacting better with more substituted alkenes.
epoxidación de alquenos
It also presents a high diastereoselectivity, better epoxidizing the less hindered face of the alkene.
epoxidation alkenes03
[1] Majority. Epoxidation on the less impeded side.
[2] Minority.
The mechanism of the epoxidation of alkenes is concerted, taking place in a single stage.
epoxidación de alquenos