JEE Main 2026 · 6 Apr · Shift 2 · Chemistry Q64

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ChemistrySingle correct+4 / -1Question 64 of 75

' $x$ ' is the product which is obtained by the hydrolysis of prop-1-yne in the presence of mercuric sulphate under dilute acidic medium at 333 K. ' $y$ ' is the product which is obtained by the reaction of ethane nitrile with methyl magnesium bromide in dry ether followed by hydrolysis. IUPAC name of product obtained from ' $x$ ' and ' $y$ ' in the presence of barium hydroxide followed by heating is :

2 - Methylpent-4-en-3-one

4 - Methylpent-3-en-2-one

4 - Methylpent-1-ene

2 - Methylpent-3-one

Answer and worked solution

Official answer: B

x and y.

Hydration of propyne ( $\ce{HgSO4}$ , dilute acid) gives acetone.
$\ce{CH3CN}$ + $\ce{CH3MgBr}$ , then hydrolysis, also gives acetone.

Aldol. Acetone with $\ce{Ba(OH)2}$ gives diacetone alcohol. Heating dehydrates it to mesityl oxide, $\ce{(CH3)2C=CH-CO-CH3}$ .

IUPAC name: 4-methylpent-3-en-2-one.

(B)

Topics:Aldol and related condensations Alkynes

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JEE Main 2026 · 6 Apr · Shift 2, Chemistry question 64