Chapter 23, Problem 23.66P

Interpretation Introduction

(a)

Interpretation:

The aromatic compound for which nitration takes place faster is to be determined.

Concept introduction:

The most important resonance contributor is with a positive charge on the atoms having all actets fulfilled. The aromatic substitution takes place faster in the compound on which a positive charge is better stabilized.

Interpretation Introduction

(b)

Interpretation:

For each of the given compounds, at which C atom electrophilic aromatic substitution to predominantly take place is to be determined. The reason for it is to be explained.

Concept introduction:

Electrophilic aromatic substitution of pyrrole takes place primarily at the 2 position preferentially over the 3 position because the corresponding arenium ion intermediate has more resonance structures and so more stable.