Question

Bouveault-Blanc reduction reaction involves :

• A. Reduction of an acyl halide with ${H2/Pd}$
• B. Reduction of an ester with ${Na/C2H5OH}$
• C. Reduction of a carbonyl compound with Na/Hg and HCl
• D. Reduction of an anhydride with ${LiAlH_4}$

Answer 1

The Correct Option is B

The Bouveault-Blanc reduction is a classic organic chemistry reaction that involves the reduction of esters to primary alcohols. This reaction utilizes metallic sodium (Na) in the presence of an alcohol, commonly ethanol (${C_2H_5OH}$), as the reducing agent. Let's understand why the correct answer is the reduction of an ester with ${Na/C_2H_5OH}$.

1. Understanding the Bouveault-Blanc Reduction: This reaction was named after the French chemists Louis Bouveault and Gustave Blanc who developed this method for reducing esters to alcohols. The reaction takes advantage of the reactivity of sodium, which donates electrons to the ester, ultimately converting it into an alcohol. The alcohol used is usually ethanol, which serves as a solvent and may also assists in the reaction mechanism.
2. Examining the Options:
   • Reduction of an acyl halide with ${H_2/Pd}$: This is typically a hydrogenation reaction used for reducing acyl halides, not esters.
   • Reduction of an ester with ${Na/C_2H_5OH}$: This is the correct description of the Bouveault-Blanc reduction, where an ester is converted into an alcohol.
   • Reduction of a carbonyl compound with Na/Hg and HCl: Generally known as the Clemmensen reduction, used for reducing ketones and aldehydes, not esters.
   • Reduction of an anhydride with ${LiAlH_4}$: While lithium aluminum hydride is a strong reducing agent capable of reducing esters as well, this specific reaction pertains to anhydrides, not esters.
3. Conclusion: Given that the Bouveault-Blanc reduction specifically involves the use of metallic sodium and an alcohol to reduce esters to alcohols, the correct statement from the options provided is the reduction of an ester with ${Na/C_2H_5OH}$. This method is historically significant and showcases an important method of reducing esters without the use of complex hydrides.