Predict the major product(S) of the following reactions and explain their formation .
`H_(3)C-CH=CH_(2)overset((Ph-CO-0)_(2))underset(HBr)rarrH_(3)C-CH=CH_(2)overset(HBr)rarr`

Explanation

In presence of organic peroxides, the addition of HBr to propene follows anti Markowinkov's rule (or peroxide effect ) to form 1-bromopropane (n-propyl bromide)

However, in absence of peroxides, addition of HBr to propene follws Markownikoff's ruls and gives 2-bromopropane as major product.
`underset("Propene")(CH_(3)-CH)=CH_(2)+H^(+)overset("show")rarrunderset(2^(@)"carbocation")underset("More stable")(CH_(3)-C^(+)H-CH_(3))overset(Br^(-))underset("Fast")rarr CH_(3)-underset(2-"bromopropane")(underset(Br)underset(|)(CH)-CH_(3))`