MolSynapsequestion bank

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

JEE Main levelSingle correct optionDifficulty 2 of 3o2024

Styrene, $C X_{6} H X_{5} - CH = CH X_{2}$ , reacts with HBr in the absence of peroxide. The major product is

A(1,2-dibromoethyl)benzene
B(2-bromoethyl)benzene
C1-bromo-4-ethylbenzene
D(1-bromoethyl)benzene

Answer: D

H

^{+}

adds to the terminal

CH X_{2}

so that the benzylic, resonance-stabilised cation

C X_{6} H X_{5} - CH X^{+} - CH X_{3}

forms. Bromide then adds to the benzylic carbon, giving

C X_{6} H X_{5} - CHBr - CH X_{3}

.

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

The rates of addition of HBr (dark) to the alkenes follow the order JEE Main level
Assertion (A): Addition of Br2 to cyclohexene gives trans-1,2-dibromocyclohexane. Reason (R): Br2 is non-polar and is polarised by the pi el... JEE Main level
2-Methylbut-2-ene, (CH3)2C=CH-CH3, reacts with HBr in the presence of peroxide. The major product is JEE Main level
(E)-But-2-ene reacts with Br2 in CCl4. The product is JEE Main level
2-Methylpropene reacts with HBr in the presence of peroxide. The major product is JEE Main level
But-1-ene is hydrated with dilute H2SO4. Which statement about the main product is correct? JEE Main level