Question

Why are epoxides important?

Answer 1

Because it is a good, general way to functionalize an olefin.

Explanation:

Given an olefinic bond, `R_1R_2C=CR_3R_4` (itself accessed by halogenation of an alkane, followed by dehydrohalogenation), the two ipso carbons may be functionalized to give an epoxide. These days, the reagents are so good, and selective that epoxidation may be done stereospecifically (i.e. depending on the geometry of the starting olefin, a given stereoisomer may be formed). Dependng on whether you are an undergraduate or not you may care to look up the so-called Sharpless peroxidation, which won its inventor a Nobel prize in 2001.