Question

Arrange the following in increasing order of their reactivity towards HCN: \[ \text{CH}_3\text{COCH}_3, \, (\text{CH}_3)_3\text{C} - \text{COCH}_3, \, \text{CH}_3\text{CHO} \]

Hint:

- Aldehydes are generally more reactive than ketones because they have a less sterically hindered carbonyl group. - The presence of bulky groups in ketones like in tert-butyl ketone reduces the reactivity towards nucleophiles.

Answer 1

The reactivity of these compounds towards HCN can be arranged in the following order: \[ (\text{CH}_3)_3\text{C} - \text{COCH}_3<\text{CH}_3\text{COCH}_3<\text{CH}_3\text{CHO} \] Aldehydes are more reactive towards HCN than ketones due to the ease with which the carbonyl carbon in aldehydes is attacked.