Question

Which of the following is most reactive towards nucleophilic addition reactions?

• A. CH\(_3\)COCH\(_3\)
• B. CH\(_3\)CHO
• C. CH\(_3\)COC\(_2\)H\(_5\)
• D. HCHO

Hint:

Reactivity order for nucleophilic addition: \[ \text{HCHO}>\text{RCHO}>\text{RCOR'} \] Aldehydes are more reactive than ketones.

Answer 1

The Correct Option is D

Step 1: Nucleophilic addition reactions occur at the carbonyl carbon, which is electrophilic in nature.
Step 2: The reactivity of carbonyl compounds towards nucleophilic addition depends on: \begin{itemize} \item Electron-donating effect of alkyl groups \item Steric hindrance around the carbonyl carbon \end{itemize}
Step 3: Formaldehyde (HCHO) has no alkyl groups attached to the carbonyl carbon, resulting in: \begin{itemize} \item Maximum electrophilicity \item Minimum steric hindrance \end{itemize}
Step 4: Hence, formaldehyde is the most reactive towards nucleophilic addition reactions.