Fundamentals of Organic ChemistryChemistryAldehydes and Ketones
Which of the following carbonyl compounds is the most stable, and which one is the least stable? (i) HCHO (ii) CH ₃ CHO (iii) CH ₃ COCH ₃ (iv) Cl ₃ CCHO
Options
- AAll four compounds are equally stable
- B(iii) is the most stable and (i) is the least stable
- C(iii) is the most stable and (iv) is the least stable
- D(iv) is the most stable and (i) is the least stable
Correct answer
C. (iii) is the most stable and (iv) is the least stable
Step-by-step solution
The stability of a carbonyl compound depends on the nature of the groups attached to the carbonyl carbon. The carbonyl carbon possesses a partial positive charge due to the higher electronegativity of the oxygen atom. Electron-donating groups, such as alkyl groups, stabilize the partial positive charge on the carbonyl carbon through the +I (inductive) effect and hyperconjugation. Conversely, electron-withdrawing groups destabilize the carbonyl carbon by intensifying the positive charge through the -I effect. In CH