Question

Why cis 1,3 dimethyl cyclohexane is more stable than its trans isomer ?

Answer 1

compounds with alkyl Equitorial substituent are generally more stable so in cis1,3 dimethyl Cyclohexan both alkyl groups are at equatorial position so it is more stable than trans 1,3 dimethyl cyclohexan in which one alkyl group is at axial and other at equatorial..

~MARK MY ANSWER AS BRAINLIEST ~

Answer 2

cis 1,3 dimethyl cyclohexane is more stable than its trans isomer due to no butane gauche interaction.

• The cis 1,3 dimethyl cyclohexane has the methyl groups in the equatorial position of the cyclohexane ring. So, it doesn't suffer from any butane gauche interaction and becomes highly stable.
• The trans 1,3 dimethyl cyclohexane has the methyl groups in the axial and equatorial position of the cyclohexane ring. So, it suffers from two butane gauche interaction and becomes less stable.