Question

Which of the following compounds on heating with potassium permanganate and dilute sulphuric acid forms adipic acid ?

• A. Methylbenzene
• B. Phenylethene
• C. Cyclohexene
• D. n-butylbenzene

Hint:

Strong oxidation of cycloalkenes with hot $\mathrm{KMnO_4}$ gives dicarboxylic acids.

Answer 1

The Correct Option is C

Step 1: Nature of reaction.
Hot, acidic potassium permanganate is a strong oxidising agent and causes oxidative cleavage of carbon–carbon double bonds.

Step 2: Oxidation of cyclohexene.
Cyclohexene undergoes oxidative cleavage of the double bond, leading to ring opening and formation of a dicarboxylic acid.

Step 3: Product formation.
The six-membered ring of cyclohexene is converted into hexanedioic acid, commonly known as adipic acid.

Step 4: Conclusion.
Therefore, the compound that forms adipic acid is Cyclohexene.