Question

Question: Identify the reagents a–c in the following scheme:

Short answer

The reagents a, b, c can be given as:

Reagent a - NaNH₂, NH₃and CH₃CH₂Br

Reagent b- H₂and Lindlar’s catalyst

Reagent c- CH₂I₂ and Zn(Cu)

Step-by-step solution

Reagents used for the conversion of alkynes to other compounds

Alkynes can be reduced to cis alkenes by treating them with hydrogen in the presence of Lindlar’s catalyst. They can also be converted to higher alkynes by treating them withNaNH₂ , ammonia and the required alkyl halide.

 Identifying the reagents for the following conversion

The first reactant, 3-methylbut-1-yne reacts with reagent a, NaNH₂, NH₃ and CH₃CH₂Br and gets converted to 2-methylhex-3-yne. This product reacts with reagent b, H₂ and Lindlar’s catalyst to form the product (Z)-2-methylhex-3-ene. This further reacts with reagent c, CH₂I₂ and Zn(Cu) to form the product (1S,2S)-1-ethyl-2-isopropylcyclopropane.

The overall reaction can be given as:

Reagents involved in the reaction