Question

Question: Draw a stepwise mechanism for the following reaction.

Short answer

Answer

Step-by-step solution

Stability of carbocation  

Carbocations are the intermediates formed in the addition reaction of alkenes.

The stability order of carbocations is $3°>2°>1°$.

1,2-hydrogen shift

The stability of carbocations is the reason for 1,2-hydrogen shift. After the shift of hydrogen to the adjacent position, the carbocation is generated, which is more stable.

Explanation

The reaction of the given compound with HBr proceeds via 1,2-hydrogen shift to generate a $3°$carbocation. The $3°$carbocation forms a tertiary halide product.

The mechanism is shown below:

Reaction mechanism