Epoxide formation [from alkenes]

Epoxide formation [from alkene] Definition:

Epoxides or oxacyclopropanes can be obtained by reaction so-called epoxidation from alkenes with peroxy acids.

Epoxide formation [from alkene] Explained:

The most commonly used peroxy acids are meta-chloroperoxybenzoic acid (MCPBA) and peroxyacetic acid.

This reaction is stereospecific. If we start with cis-alkene we will obtain cis-epoxide. The same applies to trans-isomers.