Question

The correct order of the stability for the given carbanions is:

• A. $\left(i\right)>\left(ii\right)>\left(iii\right)$
• B. $\left(iii\right)>\left(ii\right)>\left(i\right)$
• C. $\left(ii\right)>\left(i\right)>\left(iii\right)$
• D. $\left(iii\right)>\left(i\right)>\left(ii\right)$

Answer 1

The correct option is C $\left(ii\right)>\left(i\right)>\left(iii\right)$

In structure (ii) there is extended conjugation, and more delocalisation of negative charge, making it more stable than structure (ii) in which cross conjugation takes place (as shown).

In structure (iii) , there is no delocalization of electrons(or negative chaarge), thus making it the least stable.
So,the correct order of stability is:
$\left(ii\right)>\left(i\right)>\left(iii\right)$