Chapter 5.1, Problem 5.2P

Interpretation Introduction

Interpretation:

Index of hydrogen deficiency for niacin $\left(5\right)$ has to be accounted with reference to the structural formula of niacin.

Concept Introduction:

Index of hydrogen deficiency in a molecule is the total number of rings and $\text{π-}$ bonds.

$\begin{array}{l}\text{Index of hydrogen deficiency}=\frac{\left({\text{H}}_{\text{reference}}-{\text{H}}_{\text{molecule}}\right)}{2}\\ where,\\ {\text{H}}_{\text{molecule}}=\text{ Number of hydrogens in the given molecule}\text{.}\\ {\text{H}}_{\text{reference}}=\text{Number of hydrogens in the acyclicalkane }\\ \text{having same number of carbon atoms}\left({\text{C}}_{\text{n}}{\text{H}}_{\text{2n+2}}\right)\text{.}\end{array}$