Chapter 23, Problem 23.59P

Interpretation Introduction

Interpretation:

A substitution reaction is generally favored at the $\text{α}$ position over the $\text{β}$ position, which means that the arenium ion is more stable when the electrophile attaches to the $\text{α}$ position. This difference in arenium ion stabilities is to be explained.

Concept introduction:

In Friedel-Crafts acylation reaction the acyl group is added to an aromatic ring. Generally, this is done by using an acid chloride and a Lewis acid catalyst such as ${\text{AlCl}}_{\text{3}}$. The product of Friedel-Crafts acylation reaction involves ketone group with aromatic ring.

Aromaticity is a property of cyclic, planar structures with a ring of resonance bonds. Resonance provides an extra stability due to electron delocalization.