Questions: choose the correct end product 1-butyne reacts with 1) H2 / Lindlar catalyst 2) H2O / H2SO4 3) SOCl2 4) tert-butoxide / heat (A) 2-butene (B) 2-butanol (C) 1-butene (D) 1-butanol

choose the correct end product

1-butyne reacts with
1) H2 / Lindlar catalyst
2) H2O / H2SO4
3) SOCl2
4) tert-butoxide / heat
(A) 2-butene
(B) 2-butanol
(C) 1-butene
(D) 1-butanol

Transcript text: choose the correct end product 1-butyne reacts with 1) $\mathrm{H}_{2}$ / Lindlar catalyst 2) $\mathrm{H}_{2} \mathrm{O} / \mathrm{H}_{2} \mathrm{SO}_{4}$ 3) $\mathrm{SOCl}_{2}$ 4) tert-butoxide / heat (A) 2-butene (B) 2-butanol (C) 1-butene (D) 1-butanol

Solution

Solution Steps

Step 1: Analyze Reaction with $\mathrm{H}_{2}$ / Lindlar Catalyst

1-Butyne is an alkyne, and when it reacts with $\mathrm{H}_{2}$ in the presence of a Lindlar catalyst, it undergoes partial hydrogenation. The Lindlar catalyst is a poisoned catalyst that stops the hydrogenation at the alkene stage, producing a cis-alkene. Therefore, 1-butyne will be converted to cis-2-butene.

Step 2: Analyze Reaction with $\mathrm{H}_{2}\mathrm{O}$ / $\mathrm{H}_{2}\mathrm{SO}_{4}$

This reaction involves the hydration of an alkyne. In the presence of $\mathrm{H}_{2}\mathrm{SO}_{4}$, 1-butyne will undergo hydration to form a ketone. The enol intermediate tautomerizes to form 2-butanone, not an alcohol.

Step 3: Analyze Reaction with $\mathrm{SOCl}_{2}$

$\mathrm{SOCl}_{2}$ is typically used to convert alcohols to alkyl chlorides. Since 1-butyne is not an alcohol, this reaction is not applicable to 1-butyne.

Step 4: Analyze Reaction with tert-butoxide / Heat

Tert-butoxide is a strong base and is often used in elimination reactions. However, 1-butyne is already an alkyne, and elimination reactions typically apply to alkyl halides or alcohols. Therefore, this reaction does not apply to 1-butyne.