Question

Which one of the following compounds does not give benzoic acid when treated with alkaline \( KMnO_4 \)?

• A. Acetophenone
• B. n-Propyl benzene
• C. Styrene
• D. t-Butyl benzene

Hint:

Oxidation by \( KMnO_4 \) requires at least one benzylic hydrogen for conversion to benzoic acid.

Answer 1

The Correct Option is D

Step 1: Understanding Oxidation by \( KMnO_4 \) Potassium permanganate oxidizes benzylic positions to carboxyl groups if there is at least one hydrogen at the benzylic carbon. Step 2: Evaluating Each Compound - Acetophenone (\( C_6H_5COCH_3 \)) → Ketones do not undergo oxidation to benzoic acid, but side chains like methyl (–CH\(_3\)) do. - n-Propyl benzene (\( C_6H_5CH_2CH_2CH_3 \)) → Converts to benzoic acid. - Styrene (\( C_6H_5CH=CH_2 \)) → Oxidation leads to benzoic acid. - t-Butyl benzene (\( C_6H_5C(CH_3)_3 \)) → No benzylic hydrogen, thus does not undergo oxidation. Conclusion Thus, the correct answer is: \[ t\text{-Butyl benzene} \]