Chapter 23, Problem 23.3YT

Interpretation Introduction

Interpretation:

In the nitration of phenol (${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}\text{-OH}$), which arenium ion intermediate forms faster, meta or para, and which one is lower in energy is to be explained.

Concept introduction:

The substituent on the benzene ring prior to substitution dictates the regiochemistry of the reaction. Some substituents are designated as ortho/para directors because they lead to product mixtures consisting primarily of the ortho- and para-disubstituted products. Other substituents are designated as meta directors because they favor the formation of the meta-disubstituted product. The results from nitration reactions are summarized in Table 23-1:

In the nitration of phenol (${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}\text{-OH}$), the distribution of products is $\text{50\%}$ ortho, $\text{0\%}$ meta, and $\text{50\%}$ para, as given in Table 23-1.