The major product of the following reaction is:

This reaction involves Concentrated HBr (excess) and heat, which will attack two different functional groups on the molecule: the ether and the alkene.

Concentrated HBr and heat will break the aryl-alkyl ether bond.

• The Oxygen gets protonated, and the Bromide ion Br- attacks the smaller methyl group via an SN2 mechanism.
• Result: The group is converted into a Phenol, and methyl bromide is released as a by-product.

The alkene group undergoes an electrophilic addition reaction following Markovnikov's rule.

• The H+ from HBr adds to the terminal carbon to form the most stable carbocation (the benzylic carbocation).
• The Br- then attacks this stable carbocation.
• Result: The -CH=CH2 group is converted into a -CH(Br)CH3 group.