Major Product Formed in the Reaction of 3-Methyl Cyclohexene with HBr

Reaction Mechanism
The reaction of 3-methyl cyclohexene with HBr is an example of an electrophilic addition reaction. The mechanism of this reaction proceeds through the following steps:

1. The pi bond of the alkene acts as a nucleophile and attacks the electrophilic hydrogen of HBr, forming a carbocation intermediate.

2. The bromide ion acts as a nucleophile and attacks the carbocation intermediate, forming the final product.

Major Product Formed
The major product formed in the reaction of 3-methyl cyclohexene with HBr is 1-bromo-3-methylcyclohexane. This is due to the fact that the reaction proceeds through a Markovnikov addition mechanism, where the hydrogen atom of HBr adds to the carbon atom of the double bond that has the greater number of hydrogen atoms already attached to it.

Reaction Equation
The reaction equation for the reaction of 3-methyl cyclohexene with HBr is as follows:

3-Methyl Cyclohexene + HBr → 1-Bromo-3-methylcyclohexane

The reaction proceeds with the help of a catalyst, such as peroxides or light. The reaction is carried out in an inert solvent, such as ether or dichloromethane.

Conclusion
The reaction of 3-methyl cyclohexene with HBr is an example of an electrophilic addition reaction. The major product formed in this reaction is 1-bromo-3-methylcyclohexane, which is formed through a Markovnikov addition mechanism. The reaction requires a catalyst, such as peroxides or light, and is carried out in an inert solvent, such as ether or dichloromethane.