Question

Show how you would accomplish the following conversions in good yields. You may use any necessary reagents.

Short answer

The reagent used is${\mathrm{Br}}_2$,${\mathrm{PBr}}_3$ followed by hydrolysis.

Step-by-step solution

Reagent 

A reagent is a substance added in the reaction to form the product from the reaction, which means they are used to complete the chemical reactions.

HVZ reaction

It is known as Hell- Volhard- Zelinsky reaction, in which the bromine atom replaces the hydrogen of the alpha carbon to form alpha Bromo acids.

So, it is also an alpha halogenation reaction for carboxylic acids.

Reagent used in the reaction

So, as per the product formation ${\mathrm{Br}}_2,{\mathrm{PBr}}_3$is used to remove the alpha halogen from the alpha carbon of carboxylic acid formed alpha Bromo acyl bromide, which on further hydrolysis to form alpha Bromo acid as a required product.

Reaction as shown:

PRODUCT FORMATION