Question

Arrange the following compounds in their decreasing order of reactivity towards nucleophilic addition reaction.

• A. CH₃COCH₃, CH₃CO₂CH₅, CH₃CHO
• B. CH₃CO₂CH₅>CH₃COCH₃>CH₃CHO
• C. CH₃CHO>CH₃CO₂CH₅>CH₃COCH₃
• D. CH₃CHO>CH₃COCH₃>CH₃CO₂CH₅

Hint:

Aldehydes are more reactive than ketones and esters in nucleophilic addition due to the lack of electron-donating groups on the carbonyl carbon.

Answer 1

The Correct Option is D

Nucleophilic addition reactions are characterized by the addition of a nucleophile to the carbonyl carbon of an aldehyde or ketone. The reactivity of carbonyl compounds in nucleophilic addition reactions generally follows the order of Aldehyde>Ketone>Ester, with aldehydes being more reactive due to the electron-donating effect of alkyl groups in ketones and esters, which reduces the partial positive charge on the carbonyl carbon. In the given compounds: - CH₃CHO (Acetaldehyde) is the most reactive as it is an aldehyde. - CH₃COCH₃ (Acetone), a ketone, is less reactive than aldehydes. - CH₃CO₂CH₅ (Ethyl acetate), an ester, is the least reactive towards nucleophilic addition reactions due to the electron-donating effect of the ethyl group on the carbonyl carbon. Thus, the order of reactivity towards nucleophilic addition reactions is: \[ \text{CH₃CHO > CH₃COCH₃ > CH₃CO₂CH₅} \]