Chapter 10, Problem 10.54P

Interpretation Introduction

Interpretation:

It is to be identified which $\text{C}-\text{O}$ bond in the given protonated epoxide you would expect to be longer and why.

Concept introduction:

Epoxides are three membered ring ethers. Epoxides react readily with nucleophiles under neutral and basic reaction conditions. The $\text{C}-\text{O}$ bond in an epoxide partially breaks on protonation. As a result, both the carbon atoms develop a partial positive charge. The larger partial positive charge develops on the side of the ring with greater alkyl substitution. Thus, out of the two carbon atoms in the epoxide ring, the more substituted carbon atom carries the positive charge much better than the other carbon.