The final product ‘A’ in the following reaction sequence

Step-by-Step Explanation of Organic Reaction

1. First Step: Formation of an α,β-unsaturated compound

The starting molecule is butan-2-one (CH₃CH₂COCH₃), a simple ketone.

HCN (Hydrogen cyanide) is added to the ketone. This reaction is a nucleophilic addition reaction where the cyanide ion (CN⁻) adds to the carbonyl group (C=O), leading to the formation of cyanohydrin (CH₃CH₂C(CN)CH₃).

2. Second Step: Hydrolysis of Cyanohydrin

The cyanohydrin undergoes hydrolysis (using H₂O) in an acidic environment, leading to the formation of a carboxylic acid (CH₃CH₂C(CO₂H)CH₃).

The nitrile group (-CN) is converted to a carboxyl group (-COOH) in this step, converting the nitrile intermediate into butanoic acid.

3. Third Step: Elimination of Water

The carboxylic acid undergoes dehydration (using 95% H₂SO₄ and heat), which removes water and leads to the formation of methyl vinyl ketone (CH₃CH=CHCOOH), an α,β-unsaturated carboxylic acid.