Question

What are \( X \) and \( Y \) respectively in the following reaction sequence?

• A.
• B.
• C.
• D.

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. \[ \text{CH}_3\text{CH}=\text{CH}_2 + \text{HBr} \rightarrow \text{CH}_3\text{CH}_2\text{CH}_2\text{Br} \] Step 2: Wurtz Coupling Reaction - In the presence of Na and dry ether, two molecules of 1-bromopropane couple to form n-hexane.
\[ 2\text{CH}_3\text{CH}_2\text{CH}_2\text{Br} + 2\text{Na} \rightarrow \text{CH}_3\text{CH}_2\text{CH}_2\text{-CH}_2\text{CH}_2\text{CH}_3 + 2\text{NaBr} \] - This reaction confirms that \( Y \) is n-hexane.