Each Me/H, 1,3-diaxial interaction imparts `3.75` kJ `mol^(-1)` and each Me/Me, 1,3-diaxial interation imparts 15 kJ `mol^(-1)` of instability to a compound. Find the energy differences between the more stable conformers of
a. Cis - and trans-1,3-dimethyl cyclohexane.
b. (e,e) and (a,a) trans-1,2-dimethyl cyclohexane.
c. cis- and trans-1,1,3,5-tetramethyl cyclohexane.

Explanation

a.
Therefore, cis is more stable than trans isomer by `7.5 kJmol^(-1)`.
b.
Therefore, trans I (1e, 2e) is more stable than trans II (1a, 2a) by 15 kJ `mol^(-1)`.
c.
Therefore, cis from (I) is more stable than trans from (II) by `22.5 - 7.5 =15 kJ mol^(-1)` .