Question

An organic compound (A) undergoes the following reactions:

Which of the following is compound (A)?

• A. Structure 1
• B. Structure 2
• C. Structure 3
• D. Structure 4

Hint:

Key identification reactions of naphthalene: \begin{itemize} \item Partial hydrogenation gives tetralin \item Strong oxidation gives phthalic acid \end{itemize} These reactions are frequently tested in aromatic hydrocarbon problems.

Answer 1

The Correct Option is A

Given reactions:

• Reaction 1: \( \text{H}_2, \, \text{Pt} \) (Hydrogenation)
• Reaction 2: \( \text{Hot} \, \text{alk. KMnO}_4 \) (Oxidation to Carboxylic acid)
• Reaction 3: \( \text{H}^+, \, \text{H}_2\text{O} \) (Acidic Hydrolysis)

The compound (A) undergoes these reactions:

\[ \text{H}_2, \, \text{Pt} \rightarrow \text{Saturated compound} \] \[ \text{Hot alk. KMnO}_4 \rightarrow \text{Carboxylation of the methyl group} \] \[ \text{H}^+, \, \text{H}_2\text{O} \rightarrow \text{Carboxylic acid formation} \]

Step-by-Step Analysis:

Let's consider the structure of compound (A). The first reaction with hydrogen (\( \text{H}_2 \)) and platinum (\( \text{Pt} \)) suggests that the compound contains a double bond or an unsaturation. Hydrogenation would reduce the unsaturation to a saturated structure. The second reaction with hot alkaline KMnO₄ is a strong oxidizing reaction that cleaves the methyl group (\( -\text{CH}_3 \)) in methylbenzene (toluene) and oxidizes it to a carboxyl group (\( -\text{COOH} \)), forming benzoic acid. The final acidic hydrolysis ensures the formation of carboxylic acid as the final product.

Conclusion: Compound (A) is likely to be toluene (methylbenzene), and after the reactions, the product will be benzoic acid.

Therefore, compound (A) corresponds to: Option 1 (Toluene), and the final product is benzoic acid.