Chapter 14, Problem 14.9YT

Interpretation Introduction

Interpretation:

The bonds to the hydrogen atoms on the inside of the $\text{[18]annulene}$ ring are to be drawn. Whether a significant ring strain will be present in $\text{[18]annulene}$ is to be determined.

Concept introduction:

An annulene is a monocyclic hydrocarbon with the maximum possible number of alternating single and double bonds. This means each ring carbon is bonded to only one hydrogen atom. Some of these hydrogen atoms are so oriented that they project inside the ring. If the ring is small or very large, the electron clouds of some of these internal hydrogen atoms tend to interfere with each other, producing a steric strain.