Chapter 16, Problem 16.23P

Interpretation Introduction

Interpretation:

The similarities and differences that could be expected between proton NMR spectrums of compounds $\text{A}$ and $\text{B}$ are to be determined. The effect of addition of ${\text{D}}_{\text{2}}\text{O}$ on spectrum of each of the compound is to be explained.

Concept introduction:

The compounds with similar attachments in aromatic ring have same chemical shift and splitting pattern for aromatic protons in their ${}^{\text{1}}\text{H}$ NMR spectrum. The substitution at alkene carbons alters the splitting pattern of alkene protons. The intensities of the $\text{O}-\text{H}$ signal decreases dramatically, or disappears entirely by addition because of the $\text{O}-\text{H}$ proton exchange with $\text{D}$ as $\text{O}-\text{D}$.