Question

An alkene, \(\mathrm{C_4H_8}\) (\(X\)), on reaction with HBr gives a compound \(Y\). Hydrolysis of \(Y\) follows the \(S_\mathrm{N}1\) mechanism. The ozonolysis products of \(X\) are

• A. \(\mathrm{CH_3CH_2CHO,\ CH_2O}\)
• B. \(\mathrm{CH_3CHO,\ CH_3CHO}\)
• C. \(\mathrm{CH_3CH_2OH,\ CH_3CHO}\)
• D. \(\mathrm{CH_3COCH_3,\ CH_2O}\)

Hint:

A tertiary alkyl halide undergoes hydrolysis mainly by the \[ \boxed{S_\mathrm{N}1} \] mechanism. Ozonolysis cleaves the \[ \boxed{\mathrm{C=C}} \] bond into carbonyl compounds.

Answer 1

The Correct Option is D

Step 1: Identify the alkene. Hydrolysis of \(Y\) follows the \[ S_\mathrm{N}1 \] mechanism, so \(Y\) must be a tertiary alkyl bromide. The alkene that forms a tertiary bromide on addition of HBr is \[ \boxed{\mathrm{2\mbox{-}methylpropene}.} \]

Step 2: Find the ozonolysis products. Ozonolysis of \[ \mathrm{(CH_3)_2C=CH_2} \] gives \[ \mathrm{(CH_3)_2CO} \] (acetone) and \[ \mathrm{HCHO} \] (formaldehyde). That is, \[ \boxed{\mathrm{CH_3COCH_3,\ CH_2O}.} \]

Step 3: Write the answer. Hence, \[ \boxed{\mathrm{CH_3COCH_3,\ CH_2O}}. \] Thus, \[ \boxed{(D)} \] is the correct answer.