When 1-methylcyclohexene undergoes a reaction with bromine (Br2) in methanol (CH3OH), the product formed is a bromomethylcyclohexane derivative.
The reaction proceeds via an electrophilic addition mechanism. Initially, the double bond in 1-methylcyclohexene acts as a nucleophile, attacking the bromine molecule. This leads to the formation of a cyclic bromonium ion intermediate. The methanol molecule then acts as a nucleophile, attacking the more substituted carbon of the bromonium ion in a backside attack, due to steric hindrance.
This attack results in the opening of the bromonium ion and the formation of a bromo ether. The bromine atom will add to one carbon atom, while the methoxy group (-OCH3) attaches to the other carbon atom involved in the double bond. The final product is thus 1-bromo-2-methoxy-1-methylcyclohexane.