The correct stability order for the following species is
The correct stability order for the following species is
(II) $>$ (IV) $>$ (I) $>$ (III)
(I) $>$ (II) $>$ (III) $>$ (IV)
(II) $>$ (I) $>$ (IV) $>$ (III)
(I) $>$ (III) $>$ (II) $>$ (IV)
Solution
I $>$ III $>$ II $>$ IV
$+M$-effect, hyperconjugation $(6 \mathrm{Hs})$ and $+$ I-effect (2 Me groups)
$+M$-effect, hyperconjugation ( $3 \mathrm{Hs}$ ) and $+I$-effect (1 Me group)
$\overbrace{2^{\circ} \text { carbocation) }}^{+}$Hyperconjugation (5Hs) and +I-effect
Hyperconjugation (2Hs) and $+I$ effect