Some Basic Principles Of Organic Chemistry Question 210
Question: Among the given cations, the most stable carbonium ion is [IIT-JEE 1981]
Options:
A) sec-butyl
B) ter-butyl
C) n-butyl
D) None of these
Show Answer
Answer:
Correct Answer: B
Solution:
$ \underset{,3^{o}}{\mathop{CH_3-\underset{CH_3}{\overset{CH_3}{\mathop{\underset{|,}{\overset{|}{\mathop{{C^{+}},}}},}}},>}}\underset{,2{}^\circ }{\mathop{CH_3-\underset{CH_3}{\mathop{\underset{|}{\mathop{CH{{_{{}}^{{}}}^{+}}}},}},>}}\underset{\begin{matrix} \begin{matrix} {} \\ \begin{matrix} {} \\ 1^{o} \\ \end{matrix} \\ \end{matrix} \\ \\ \end{matrix}}{\mathop{CH_3-CH{{_2^{{}}}^{+}}}},>\underset{\begin{matrix} {} \\ \begin{matrix} {} \\ \begin{smallmatrix} \text{Methyl } \\ carbocation \end{smallmatrix} \\ \end{matrix} \\ \end{matrix}}{\mathop{CH{{_3^{{}}}^{+}},}}, $ Greater the no.
of alkyl groups, greater would be the dispersal of the charge and hence more stable will be the carbonium ion.
