Chemistry · Hydrocarbons

JEE Main 2024 — 29 January, Shift 1 — Question 70

The final product A formed in the following multistep reaction sequence is

Option A:
Correct
Option B:
Option C:
Option D:

Answer: A

Step-by-step solution

The starting compound is allylbenzene, $\mathrm{C_6H_5{-}CH_2{-}CH{=}CH_2}$ . Step (i):} $\mathrm{H_2O, H^+}$ : Acid-catalysed hydration of the alkene gives a secondary alcohol at the benzylic side chain.

Step (ii): $\mathrm{CrO_3}$ : Oxidation of the secondary alcohol forms a ketone.

Step (iii): $\mathrm{H_2N{-}NH_2,\ KOH,\ heat}$ : Wolff-Kishner reduction converts the ketone into a methylene group.

Thus, the side chain is reduced to an ethyl group, and the final product is $\mathrm{C_6H_5{-}CH_2{-}CH_3}$ .

Hence, the final product $A$ is ethylbenzene, corresponding to Option A.

Answer key and solution verified before publishing.

Practise Hydrocarbons

Start with this question, then two more from the same chapter — with a tutor that explains every step. Free.

Solve a similar one free

Exam: JEE Main 2024
Paper: 29 January, Shift 1
Subject: Chemistry
Chapter: Hydrocarbons
Topic: Properties & Uses of Alkenes and Dienes