Question

HVZ reaction is specific for:

• A. Replacement of $\beta$ - hydrogen
• B. Replacement of $\alpha$ - hydrogen
• C. Replacement of $\beta$ - carbons
• D. Replacement of $\alpha$ - carbons

Answer 1

The correct option is B Replacement of $\alpha$ - hydrogen

In the presence of phosphorus, aliphatic Carboxylic acids react smoothly with chlorine or bromine to yield a compound in which $\alpha$ – hydrogen has been replaced by halogen. Such reaction is known as Hell–volhard–Zelinsky reaction.