Question

The reaction of 2,2-dimethyl-1-piopanol with HBr is very slow and gives 2-bromo- 2-methyIbutane as the major product. Give a mechanistic explanation for these observations. Select all that apply. Stereoelectronic effects result in an antic op lanar rearrangement of the carbon skeleton. Steric hindrance prevents nucleophilic attack. The mechanism requites the development of an unstable positively charged species in the transition state. The mechanism results in a carbocation rearrangement in which a methyl shift occurs. The mechanism requires dissociation of a poor leaving group.

Answer 1

Answer:

Correct option : "The mechanism results in a carbocation rearrangement in which a methyl shift occurs"

Explanation:

In the first step, 2,2-dimethyl-1-propanol gets protonated.

In the second step, a carbocationic intermediate is produced from removal of $H_{2}O$.

In the third step, shifting of methyl group occurs to produce more stable carbocationic intermediate.

In the fourth step, $Br^{-}$ attacks the stable carbocation to produce 2-bromo-2-methylbutane.

So, correct option : "The mechanism results in a carbocation rearrangement in which a methyl shift occurs"

Full reaction mechanism has been shown below.