NTA Abhyas JEE Main2020ChemistryGeneral Organic ChemistryPractice
Rank the following carbocations in order of stability (1 = most stable)
Options
- AA → 2, B → 1, C → 3, D → 4
- BA → 4, B → 2, C → 1, D → 3
- CA → 4, B → 3, C → 2, D → 1
- DA → 1, B → 2, C → 3, D → 4
Correct answer
A. A → 2, B → 1, C → 3, D → 4
Step-by-step solution
A -2 [3 o carbocation with cross conjugation] B - 1 [2 o carbocation with extended conjugation ] C - 3 [3 o carbocation with 4 hyperconjugations and +I of 3 alkyl groups] D - 4 [2 o carbocation with 2 hyperconjugations and +I of 2 alkyl groups] So order will be A → 2, B → 1, C → 3, D → 4