Question

Identify A, B and C in below reaction:

• A. A=Br², B=KOH, C=NaNH²
• B. A-Br², B=HCl, C-NaNH²
• C. A=Br², B=HCl, C=NaNH⁴
• D. A=Br², B=KOH, C=NaNH²

Answer 1

The Correct Option is D

To identify A, B, and C in the given reaction sequence, let's analyze each step: 

Reaction with A: The initial compound contains an alkene group. When alkenes react with bromine \((\text{Br}_2)\), an anti-addition reaction occurs, leading to vicinal dibromides. Hence, A = Br².

Reaction with B: The dibromide undergoes dehydrohalogenation. With alcoholic KOH, elimination occurs, forming an alkyne. Therefore, B = KOH.

Reaction with C: The alkyne can undergo further deprotonation when reacted with sodium amide \((\text{NaNH}_2)\) to form a more reactive acetylide ion. Thus, C = NaNH².

Therefore, the correct sequence is: A=Br², B=KOH, C=NaNH².