Answer
The reaction is free-radical addition of HBr. It is a anti-markovnikov addition of Br. The proposed mechanism is shown below.
Work Step by Step
Initiation: Formation of radicals.
One electron in the bond between the O-O goes to the R on the left side and one electron goes to the R on the right.
Propagation: A radical reacts to generate another radical.
- Step 1: A bromine radical adds to the double bond to generate an alkyl radical on the more substituted carbon atom.
- Step 2: The alkyl radical abstracts a hydrogen atom from HBr to generate the product and a bromine radical.
The bromine radical generated in Step 2 goes on to react with another molecule of alkene in Step 1, continuing the chain.
Propagation: A radical reacts to generate another radical.
