An organic compound (A) on catalytic hydrogenation with \( \mathrm{H_2/Pt} \) gives tetralin, and on oxidation with hot alkaline \( \mathrm{KMnO_4} \) followed by acidification gives phthalic acid. Identify compound (A).
Show Hint
Fused aromatic hydrocarbons like naphthalene:
\begin{itemize}
\item Give phthalic acid on strong oxidation
\item Give tetralin on partial catalytic hydrogenation
\end{itemize}
These reactions are commonly used for identification.
To identify the organic compound (A), we need to consider the reactions it undergoes:
Catalytic Hydrogenation: Compound (A) reacts with \( \mathrm{H_2/Pt} \) to give tetralin. Tetralin is also known as tetrahydronaphthalene, which has a fully saturated cyclohexane ring fused to a benzene ring.
Oxidation Reaction: Compound (A) on oxidation with hot alkaline \( \mathrm{KMnO_4} \) followed by acidification yields phthalic acid, which is a benzene ring with two adjacent carboxylic acid groups.
From the information given, compound (A) needs to have a naphthalene structure with a partial unsaturation that hydrogenates to form tetralin and oxidizes to form phthalic acid. This corresponds to 1,2-dihydronaphthalene.
Hence, option a is correct. Compound (A) is 1,2-dihydronaphthalene.
