Chapter 6: C=C + peracid

Chapter 6: Reactions of Alkenes: Addition Reactions

Epoxidation of Alkenes

Reaction type: Electrophilic Addition

Summary

Overall transformation :C=C to epoxide
Reagent : a peracid or peroxyacid, RCO₃H
Regioselectivity : not relevant since both new bonds are the same,C-O
Stereoselectivity : syn since the two new C-O s bonds form at the same time from the peracid.

Questions
What other functional group description could be given to an epoxide ?

What other addition reactions convert an alkene into a three membered ring ?

MECHANISM FOR REACTION OF ALKENES WITH PERACID
A single step reaction involving several changes. Start at the C=C as the nucleophile, make a bond to the slightly electrophilic O, break the weak O-O bond and form a C=O, break the original C=O to make a new O-H bond, break the original O-H to form the new C-O bond ! (phew !)