The major product of the following chemical reaction is : [figure]
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Answer
(1) [figure]
Solution
As per NCERT, in the presence of a peroxide such as benzoyl peroxide, HBr adds to an unsymmetrical alkene contrary to Markovnikov's rule (peroxide effect / Kharash effect), by a free-radical mechanism.
The peroxide gives phenyl radicals, (C6H5CO)2O2 2C6H5 CO2 2 C6H5 + 2CO2, which take H from HBr: C6H5 + HBr C6H6 + Br.
Br then adds to the terminal CH2 so that the more stable 2° radical, (CH3)2CH- CH-CH2Br, is formed, and this radical takes H from HBr:
(CH3)2CH- CH-CH2Br + HBr (CH3)2CH-CH2-CH2Br + Br
∴ Major product: 1-bromo-3-methylbutane, (CH3)2CH-CH2-CH2-Br
Answer: (1)