Question

Which of the following are correct?

(i) \[\ce{CH3 - O - CH^{⊕}2}\] is more stable than \[\ce{CH3 - CH^{⊕}2}\]

(ii) (CH₃)₂CH^⊕ is less stable than \[\ce{CH3 - CH2 - CH^{⊕}2}\]

(iii) \[\ce{CH3 = CH2 - CH^{⊕}2}\] is more stable than \[\ce{CH3 - CH2 - CH^{⊕}2}\]

(iv) \[\ce{CH2 - CH^{⊕}}\] is more stable than \[\ce{CH3 - CH^{⊕}2}\]

Answer 1

(i) \[\ce{CH3 - O - CH^{⊕}2}\] is more stable than \[\ce{CH3 - CH^{⊕}2}\]

(iii) \[\ce{CH3 = CH2 - CH^{⊕}2}\] is more stable than \[\ce{CH3 - CH2 - CH^{⊕}2}\]

Explanation:

The +1 effect of the –OCH₃ group stabilizes the carbocation.

The two resonating structure of \[\ce{CH2 = CH - CH2^{⊕}↔^⊕CH2 - CH = CH2}\] makes it more stable.