Manipal MET2021ChemistryGeneral Organic Chemistry
Which is the decreasing order of stability? (i) CH ₃- + C H - CH ₃ (ii) CH ₃- + C H - O - CH ₃ (iii) CH ₃ + C H CO CH ₃
Options
- A(i) < (ii) < (iii)
- B(i) (ii) (iii)
- C(iii) (i) (ii)
- D(ii) (iii) (i)
Correct answer
B. (i) (ii) (iii)
Step-by-step solution
Presence of -/ group in a carbocation decreases delocalisation of the positive charge and hence decreases stability of the carbocation and vice versa. Thus the carbocation (iii) having - COCH ₃ grouping is the least stable, followed by (ii) having - OCH ₃ grouping, followed by (i) having only alkyl group.