MolSynapsequestion bank

MolSynapse / Question bank / Organic Reaction Mechanisms II: Electrophilic and Radical Reactions / Electrophilic addition to alkenes and Markovnikov rule

JEE Main levelOne or more correct optionsDifficulty 2 of 3o2031

Cyclopentene reacts with $Br X_{2}$ in $CCl X_{4}$ . Select the correct statements.

AThe product is trans-1,2-dibromocyclopentane
BThe product is a racemic mixture of the (1R,2R) and (1S,2S) isomers
CThe product is the meso (cis) isomer
DThe reaction proceeds through a cyclic bromonium ion

Answer: A, B, D

The cyclic bromonium ion is opened by

Br X^{-}

from the opposite face, so the product is trans. The trans-1,2-dibromocyclopentane is chiral, and attack on either carbon is equally likely, giving a racemic (1R,2R)/(1S,2S) mixture. The meso cis isomer is not formed.

Practice Organic Reaction Mechanisms II: Electrophilic and Radical Reactions More on Electrophilic addition to alkenes and Markovnikov rule

Previous questionNext question

More questions on Electrophilic addition to alkenes and Markovnikov rule

Propene reacts with HOCl (chlorine water). The major product is JEE Main level
3,3,3-Trifluoropropene, CF3-CH=CH2, reacts with HBr in the dark. The major product is JEE Main level
Select the reactions that give the 1-bromo (terminal bromide) compound as the major product. JEE Main level
Which reagent combinations convert propene mainly into propan-2-ol? JEE Main level
Select the correct statements about carbocation stability. JEE Main level
4-Methylpent-1-ene, (CH3)2CH-CH2-CH=CH2, reacts with HBr in the dark. Which is the major product? JEE Advanced level