Which among the following aldehydes is most reactive towards nucleophilic addition reactions?
- C2H5- O \|C-H
- H- O \|C-H
- C3H7- O \|C-H
- CH3- O \|C-H
Answer
(2) H- O \|C-H
Solution
Reactivity towards nucleophilic addition ∝ + on carbonyl carbon and ∝ 1steric hindrance
∵ HCHO has no electron-donating (+I) alkyl group and the least crowding at C=O ⇒ most electrophilic carbonyl carbon
∴ HCHO > CH3CHO > C2H5CHO > C3H7CHO
Answer: (2)