Chapter 20, Problem 20.21P

Interpretation Introduction

(a)

Interpretation:

The reaction mechanism for the conversion of benzoic acid into phenylacetic acid, ${\text{PhCH}}_{\text{2}}{\text{CO}}_{\text{2}}\text{H}$ is to be stated.

Concept introduction:

Carboxylic acids can be reduced by using strong reducing agents like ${\text{LiAlH}}_{\text{4}}$ or ${\text{NaBH}}_{\text{4}}$ to alcohols. Alcohols reacts with halogen hydrides to form alkyl halides which on reaction with magnesium in dry ether to form Grignard reagent which further reacts with carbon dioxide to give a carboxylic acid with increased number of carbon atoms in the carbon chain.

Interpretation Introduction

(b)

Interpretation:

The reaction mechanism for the conversion of benzoic acid into $\text{3-phenylpropanoicacid}$ is to be stated.

Concept introduction:

Carboxylic acids can be reduced by using strong reducing agents like ${\text{LiAlH}}_{\text{4}}$ or ${\text{NaBH}}_{\text{4}}$ to alcohols. Alcohols reacts with halogen hydrides to form alkyl halides which on reaction with Grignard reagent and carbon dioxide gives a carboxylic acid with increased number of carbon atoms in the carbon chain.