Question

Nucleophilic addition of ammonia and its derivatives does not occur with carbonyl group in strongly acidic medium.

Hint:

In organic chemistry, "Strongly Acidic" often means a basic reagent will be neutralized and rendered unreactive.

Answer 1

Step 1: Understanding the Concept:
Nucleophilic addition requires a free lone pair on the nucleophile to attack the carbonyl carbon.
Step 2: Detailed Explanation:
Ammonia and its derivatives (\( NH_2-G \)) are basic in nature due to the lone pair on the nitrogen atom.
In a strongly acidic medium, these derivatives get protonated to form ammonium ions (\( [NH_3-G]^+ \)).
Once protonated, the nitrogen no longer has a lone pair of electrons.
Therefore, it cannot act as a nucleophile and cannot attack the carbonyl group.
This is why these reactions are carried out at a controlled pH (around 3.5).
Step 3: Final Answer:
The reaction fails in strong acid because the nucleophile itself gets protonated and loses its nucleophilic character.