Question

The reaction of 2,2-dimethylpentan-3-one with bromine yields a monobrominated product in acidic medium but gives a dibrominated product in basic medium. Draw the products of each reaction and propose an explanation as to why there is a difference in reactivity between acidic and basic media.

Answer 1

The reactions mechanisms and products structures are in the attached picture.

Step-by-step explanation:

The acid-catalysed bromination of ketones leads to a monobrominated product. The first step of the reaction occurs in a cyclic way. The addition of more bromines is not possible due to steric impediment

The base-catalysed bromination of ketones leads to a dibrominated product.