Question

What are \( X \) and \( Y \) respectively in the following reaction sequence? \begin{center} \includegraphics[]{139.png} \end{center}

• A. \includegraphics[]{139a.png}
• B. \includegraphics[]{139b.png}
• C. \includegraphics[]{139c.png}
• D. \includegraphics[]{139d.png}

Hint:

The peroxide effect results in anti-Markovnikov addition of HBr, and the Wurtz reaction forms higher alkanes by coupling alkyl halides.

Answer 1

The Correct Option is D

Step 1: Anti-Markovnikov Addition of HBr
- Due to the presence of benzoyl peroxide, the reaction follows the peroxide effect (Kharasch effect).
- This means Br attaches to the less substituted carbon, forming 1-bromopropane. \[ {CH}_3{CH}={CH}_2 + {HBr} \rightarrow {CH}_3{CH}_2{CH}_2{Br} \] Step 2: Wurtz Coupling Reaction - In the presence of Na and dry ether, two molecules of 1-bromopropane couple to form n-hexane.
\[ 2{CH}_3{CH}_2{CH}_2{Br} + 2{Na} \rightarrow {CH}_3{CH}_2{CH}_2{-CH}_2{CH}_2{CH}_3 + 2{NaBr} \] - This reaction confirms that \( Y \) is n-hexane.