Question

An alkyl halide C\(_4\)H\(_8\)Br(X) undergoes hydrolysis preferably in polar protic solvents. X can be prepared from which of the following reactants? 

• A.
• B.
• C.
• D.

Hint:

In the presence of HBr alone, alkenes undergo Markovnikov addition, while in the presence of peroxides, they undergo anti-Markovnikov addition.

Answer 1

The Correct Option is A

To determine the correct preparation method for C₄H₈Br, let's analyze the reactants:

1. First option: The reaction of an alkene with HBr follows Markovnikov’s rule, leading to the formation of the most stable alkyl halide. This is the correct method.

2. Second option: The presence of peroxide (C₆H₅CO)₂O₂ leads to anti-Markovnikov addition, forming a different product.

3. Third option: Bromination with Br₂/heat leads to the formation of a different type of brominated product (not an alkyl halide via hydrohalogenation).

4. Fourth option: Again, HBr in the presence of peroxides gives anti-Markovnikov addition, which is not the desired product.

Thus, the correct reaction is HBr addition following Markovnikov’s rule, making option (1) the correct choice.