Explain why neopentyl chloride cannot be prepared by the action of HCl on neopentyl alcohol.

Answer : Neopentyl cation has a strong tendency to rearrange from less stable 1° carbocation to a more stable 3° carbocation. Hence, we get 2-chloro-2-methylbutane instead of neopentyl chloride.

How to prepare neopentyl chloride:

Since free radicals usually do not rearrange, the best method to prepare neopentyl chloride is by photo-chemical free-radical chlorination of neopentane.