Hydrocarbons Question 48

Question: 3-Phenylpropene on reaction with HBr gives (as a major product) [AIIMS 2005]

Options:

A) $ C_6H_5CH_2CH(Br)CH_3 $

B) $ C_6H_5CH(Br)CH_2CH_3 $

C) $ C_6H_5CH_2CH_2CH_2Br $

D) $ C_6H_5CH(Br)CH=CH_2 $

Show Answer

Answer:

Correct Answer: B

Solution:

According to Markownikoff’s rule, the negative part of the unsymmetrical reagent adds to less hydrogenated (more substituted) carbon atom of the double bond.

$C_6H_5CH = CH - CH_3 + HBr $

$ \overset{\overset{Br}{\mathop{|}}}{\mathop{C_6H_5CHC{H _{_2}}CH_3}} $