Question

Arrange in the correct order of stability (decreasing order) for the following molecules :

• A. $\left(I\right)>\left(II\right)>\left(III\right)>\left(IV\right)$
• B. $\left(IV\right)>\left(III\right)>\left(II\right)$ $\approx$ $\left(II\right)$
• C. $\left(I\right)>(II$) $\approx$ $\left(III\right)>\left(IV\right)$
• D. $\left(III\right)>\left(I\right)$ $\approx$ $\left(II\right)>\left(IV\right)$

Answer 1

The correct option is D $\left(III\right)>\left(I\right)$ $\approx$ $\left(II\right)>\left(IV\right)$

Disequatorial $cis-1,3-Dimethylcyclohexane$ is more stable as both methyl groups are equatorial and are away from each other.

(Refer to Image 1)

It is followed by $trans-1,3-Dimethylcyclohexane$ where one $-C{H}_3$ group is equatorial & other is axial

(Refer to Image 2)

Diaxial $cis-1,3-Dimethylcyclohexane$ is less stable due to large amount of steric strain due to the interaction of axial $-C{H}_3$ groups.

(Refer to Image 3)

$\left(III\right)>\left(I\right)\approx \left(II\right)>\left(IV\right)$