Question

Which of the following compounds does not react with $NaHS{O}_3$?

• A. $HCHO$
• B. $C_6{H}_{5}COC{H}_3$
• C. $C{H}_{3}COC{H}_3$
• D. $C{H}_{3}CHO$

Answer 1

The correct option is B $C_6{H}_{5}COC{H}_3$

$NaHS{O}_3$ addition to carbonyl compound is an example of nucleophilic addition reaction.
Mechanism of addition of $NaHS{O}_3$ involves 2 steps.
Step-1: Nucleophilic attack on ​carbonyl carbon:
Step-2: Formation of an adductAcetophenones do not undergo this reaction because nucleophile is less approachable to the carbonyl carbon as it is more bulkier group present ​in this ketone.