Transcribed text From Image: Which of the following is the most stable cation? a) A b) B c) C d) D
Expert Chegg Question Answer:
Stability order for carbocations follows the order, 30 > 20 > 10.
In 30 carbocation 3 alkyl groups stabilizes +ve charge on central carbon through their electron donating inductive effect (+I effect) moreover in 30 carbocation relatively more hyperconjugative structures possible which provides extra stability to it.
Whereas in 20 only 2 alkyl and in 10 only 1 alkyl group will be there to stabilize carbocation through +I effect and also relatively less number of hyperconjugative structures possible for them and hence they are relatively less stable than 30 carbocation.
In given examples tert-Butyl carbocation (Option-C ) is the only 30 carbocation and hence is the most among the all given carbocations.
For t-Butyl carbocation there are 9 hyperconjugative structures possible.