CH3 - CH = CH2(propane) + HBr \(\overset{(C_6H_5CO)_2 O_2}{\longrightarrow}\) CH3 - CH2 - CH2 - Br (1- bromopropane)
The reaction proceeds through freee radical mechanism:
Step 1.
The weak O-O single bond linkage of peroxide undergoes homolytic cleavage to generate free radical.
Step 2.
The radicals abstracts a hydrogen atom from HBr thus generating bromine free radical.
Step 3.
The Bromine free radical adds lo the double bond in the way so as to form the more stable alkyl free radical,
Step 4.
Addition of HBr to secondary free radical.