Question
Decreasing order of stability of following alkenes is
\[\begin{align}
& \left( \text{i} \right)C{{H}_{3}}-CH=C{{H}_{2}} \\
& \left( \text{ii} \right)C{{H}_{3}}-CH=CH-C{{H}_{3}} \\
& \left( \text{iii} \right)C{{H}_{3}}\underset{\begin{smallmatrix}
| \\
\,\,\,C{{H}_{3}}
\end{smallmatrix}}{\mathop{-\,\,C=}}\,CH-C{{H}_{3}} \\
& \left( \text{iv} \right)C{{H}_{3}}\,\,\overset{\begin{smallmatrix}
\,\,\,\,C{{H}_{3}} \\
|
\end{smallmatrix}}{\mathop{-\,\,C\,=}}\,\overset{\begin{smallmatrix}
\,\,\,\,C{{H}_{3}} \\
|
\end{smallmatrix}}{\mathop{\,\,\,C\,\,-}}\,\,\,C{{H}_{3}} \\
\end{align}\]
A.
(i) > (ii) > (iii) > (iv)
B.
(iv) > (iii) > (ii) > (i)
C.
(iii) > (ii) > (i) > (iv)
D.
(ii) > (iii) > (iv) > (i)
Answer :
(iv) > (iii) > (ii) > (i)
Solution :
Higher the number of \[\alpha -H,\] more the hyperconjugating structures, more the stability of the compound.