Chapter 16, Problem 16.5P

Interpretation Introduction

(a)

Interpretation:

Whether the given compound is aromatic is to be stated.

Concept introduction:

Aromatic compounds are those compounds which follow the Huckel’s rule of aromaticity and are planar with $s{p}^2$ hybridized atoms. According to Huckel’s rule, a compound is aromatic if the total number of electrons in the ring follows $\left(4\text{n}+2\right)\pi$ electrons rule.

Interpretation Introduction

(b)

Interpretation:

The two sets of resonances in NMR spectrum of the given compound are to be assigned. The explanation as to why there is difference in the chemical shifts is to be stated. Also, the explanation as to why one of the chemical shifts is so small is to be stated.

Concept introduction:

The number of NMR signal in a compound is equal to the number of chemically non-equivalent protons present in that compound. The more the shielded proton less will be its chemical shift value and the corresponding signal will be produced at the right-hand side or lower frequency region or vice versa.