JEE Main · 2025 · 07 Apr 2025 · Shift 1 · General Organic Chemistry

Which of the following is the correct IUPAC name of given organic compound (X) ?

(see structure)

(A)2-Bromo-2-methylbut-2-ene
(B)3-Bromo-3-methylprop-2-ene
(C)1-Bromo-2-methylbut-2-ene✓ Correct
(D)4-Bromo-3-methylbut-2-ene

Answer: (C)

Solution

The parent chain is the four-carbon chain carrying the carbon-carbon double bond, so the base name is butene. Numbering follows the lowest set of locants: starting from the carbon of the bromomethyl end places the double bond at C2--C3, the methyl branch at C2 and the bromine at C1, a set of

{1, 2}

, while starting from the other end would give

{3, 4}

. The lower set is chosen, so the substituents are 1-bromo and 2-methyl on but-2-ene. The compound is 1-bromo-2-methylbut-2-ene.

JEE Main · 2025 · 07 Apr 2025 · Shift 1 · Single correct option

Practise more: all JEE Main PYQs on General Organic Chemistry →

More JEE Main questions on General Organic Chemistry

From the following, the least stable structure is:
JEE Main 2026View solution →
Identify correct statement from the following:

A. Propanal and propanone are functional isomers.
B. Ethoxyethane and methoxypropane are metamers.
C. But-2-ene shows optical isomerism.
D. But-1-ene and but-2-ene are functional isomers.
E. Pentane and 2, 2-dimethyl propane are cha …
JEE Main 2026View solution →
Match List-I with List-II.

List-I (Pair of Compounds):
A. 2-Methylpropene and but-1-ene
B. Cis-but-2-ene and trans-but-2-ene
C. 2-Butanol and diethyl ether
D. But-1-ene and but-2-ene

List-II (Type of Isomers):
I. Stereoisomers
II. Position isomers
III. Chain isomers
IV. Functio …
JEE Main 2026View solution →
Given below are two statements:

Statement-I: Compound (X), shown below, dissolves in $NaHCO_{3}$ solution and has two chiral carbon atoms

Statement-II: Compound (Y), shown below, has two carbons with $sp^{3}$ hybridization, one carbon with $sp^{2}$ an …
JEE Main 2026View solution →
The IUPAC name of the following comopound is :
JEE Main 2026View solution →
Consider all the structural isomers with molecular formula $C X_{5} H X_{11} Br$ are separately treated with KOH (aq) to give respective substitution products, without any rearrangement. The number of products which can exhibit optical isomerism from these is ____ .
JEE Main 2026View solution →