0
$\begingroup$

Carbo-cations may be stabilized by:
(a) π-bonds only at allylic position
(b) π-bonds only at vinylic position
(c) π-bonds at allylic and benzylic position also (d) -I effect

While the answer is obviously not (d), I am really confused about what 'allylic', 'vinylic' and 'benzylic' positions actually mean. I have heard about allylic/vinylic/benzylic carbons, but positions..?

Please, help.
Thank-you.




The question has been taken from ADVANCED PROBLEMS IN ORGANIC CHEMISTRY by HIMANSHU PANDEY

Improve this question
$\endgroup$

2 Answers 2

Reset to default
3
$\begingroup$

For carbocation stability, think about which case has opportunity for electron resonance, i.e., which case(s) allows the positive charge to be delocalized to adjacent pi bonds. This resource might help.

Improve this answer
$\endgroup$
0
1
$\begingroup$

Allylic position is the same as allylic carbon....similarly for vinylic and benzylic...so the stability of carbocations goes as

benzylic > allylic > vinylic vinyl carbocations moreover are highly unstable...whereas the other two are rather stable ones...and the answer is (C) enter image description here enter image description here

Improve this answer
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.