The most suitable reagent for the following conversion, is : H₃C-Cequiv C-CH₃ → cis-2-butene 1. Na / liquid NH ₃ 2. H ₂ , Pd/C, quinoline 3. Zn/HCl 4. Hg ²⁺ /H ^+ , H ₂ O

Answer: 2. H ₂ , Pd/C, quinoline Partial reduction of an alkyne to a cis-alkene needs syn addition of H₂ on a poisoned catalyst, i.e. Lindlar's catalyst (Pd/C with quinoline). H₂,\ Pd/C,\ quinoline : but-2-yne to cis-but-2-ene. Na/liq.\ NH₃ : anti addition, gives trans-2-butene. Zn/HCl : not used for alkyne reduction. mathrmHg²⁺/H^+,\ H₂O : hydration, gives butanone. Answer: option (2).

Topic: Alkynes: acidic character and addition reactions· Hydrocarbons

The most suitable reagent for the following conversion, is :H_3C-C C-CH_3 → cis-2-butene

The most suitable reagent for the following conversion, is :

\(H_3C-C\equiv C-CH_3 \to\) cis-2-butene

but-2-yne to cis-2-butene conversion scheme

1. Na / liquid NH\(_3\)

2. H\(_2\), Pd/C, quinoline

3. Zn/HCl

4. Hg\(^{2+}\)/H\(^+\), H\(_2\)O

Doubtly Asked 30 Oct 2026 NEET UG 2019 Practice test neet Save WhatsApp Report

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Answer: 2. H\(_2\), Pd/C, quinoline

Partial reduction of an alkyne to a cis-alkene needs syn addition of \(\mathrm{H_2}\) on a poisoned catalyst, i.e. Lindlar's catalyst (Pd/C with quinoline).

\(\mathrm{H_2,\ Pd/C,\ quinoline}\): but-2-yne to cis-but-2-ene.
\(\mathrm{Na/liq.\ NH_3}\): anti addition, gives trans-2-butene.
\(\mathrm{Zn/HCl}\): not used for alkyne reduction.
\(\mathrm{Hg^{2+}/H^+,\ H_2O}\): hydration, gives butanone.

Answer: option (2).

Doubtly AI · 30 Oct 2026 AI-generated · not yet verified Report

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The most suitable reagent for the following conversion, is :H_3C-C C-CH_3 → cis-2-butene

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