Question

Which of the following is least reactive towards a nucleophilic attack?

(a) Acetaldehyde

(b) Butanone

(c) Diisopropyl ketone

(d) Ditert-Butyl ketone

The question was asked during an interview.

My doubt stems from Aldehydes and Ketones Chemical Reactions in section Aldehydes, Ketones and Carboxylic Acids of Chemistry – Class 12

Answer 1

Right answer is (d) Ditert-Butyl ketone

For explanation: The stearic effects come into consideration when comparing these compounds. Ditert-Butyl ketone has two very bulky tert-butyl groups, one on either side of the carbonyl carbon. This increases the hinderance to the incoming nucleophile and decreases the reactivity.