JEE Main · 2021 · 31 Aug 2021 · Shift 1 · Aldehydes Ketones and Carboxylic Acids

The major products A and B in the following set of reactions are :

(A)(see structures)
A
B
(B)(see structures)
✓ Correct
(C)(see structures)
(D)(see structures)

Answer: (B)

Solution

The substrate is acetone cyanohydrin,

(C H_{3})_{2} C (OH) CN

. Lithium aluminium hydride reduces the nitrile to a primary amine, so after work-up A is 1-amino-2-methylpropan-2-ol,

(C H_{3})_{2} C (OH) C H_{2} N H_{2}

. Warm aqueous sulphuric acid hydrolyses the nitrile to a carboxylic acid and dehydrates the tertiary alcohol, so B is the

α, β

-unsaturated acid 2-methylprop-2-enoic acid,

C H_{2} = C (C H_{3}) COOH

JEE Main · 2021 · 31 Aug 2021 · Shift 1 · Single correct option

Practise more: all JEE Main PYQs on Aldehydes Ketones and Carboxylic Acids →

More JEE Main questions on Aldehydes Ketones and Carboxylic Acids

An organic compound "P" of molecular formula $C_{6} H_{12} O_{3}$ gives positive iodoform test but negative Tollen's test. When "P" is treated with dilute acid, it produces "Q". "Q" gives positive Tollen's test and also iodoform test. The structure of …
JEE Main 2026View solution →
Match List-I with List-II.

List-I (Reaction Name - Involving aldehydes):
I. Etard Reaction
II. Rosenmund Reduction
III. Gatterman-Koch Reaction
IV. Stephen Reaction

List-II (Reagents):
A. $H_{2}$ , Pd- $BaSO_{4}$
B. $SnCl_{2}$ , HCl
C. …
JEE Main 2026View solution →
The compound A, $C_{8} H_{8} O_{2}$ reacts with acetophenone to form a single product via cross-Aldol condensation. The compound A on reaction with conc. NaOH forms a substituted benzyl alcohol as
JEE Main 2026View solution →
' $x$ ' is the product which is obtained from propanenitrile and stannous chloride in the presence of hydrochloric acid followed by hydrolysis. ' y ' is the product which is obtained from the but-2-ene by the ozonolysis followed by hydrolysis. From the following, which product is …
JEE Main 2026View solution →
From the given following (A to D) cyclic structures, those which will not react with Tollen's reagent are :
JEE Main 2026View solution →
Iodoform test can differentiate between
A. Methanol and Ethanol
B. $CH_{3} COOH$ and $CH_{3} CH_{2} COOH$
C. Cyclohexene and cyclohexanone
D. Diethyl ether and Pentan-3-one
E. Anisole and acetone

Choose the correct answer from the …
JEE Main 2026View solution →