oxidation reaction of alkene

Oxidation reactions of alkenes give cyclic ethers in which both carbons of a double bond become bonded to the same oxygen atom. 

These products are called epoxides or oxiranes.

 An important method for preparing epoxides is by reaction with peracids, RCO₃H.

The epoxidation reaction occurs in a single step with a transition state.

 Consequently, epoxidations by peracids always have syn-stereoselectivity

Epoxides may be cleaved by aqueous acid to give glycols that are often diastereomeric with those prepared by the syn-hydroxylation reaction described above.

Proton transfer from the acid catalyst generates the conjugate acid of 

the epoxide, which is attacked by nucleophiles such as water .

The result is anti-hydroxylation of the double bond .

 In the following equation this procedure is illustrated for a cis-

disubstituted epoxide, which, of course, could be prepared from the

 corresponding cis-alkene. This hydration of an epoxide does not change 

the oxidation state of any atoms or groups.