Why is trans-1,2-dimethylcyclohexane more thermodynamically stable than cis-1,2-dimethylcyclohexane in its chair conformation?
Answer and explanation
Correct answer: B. Both methyl groups can simultaneously occupy equatorial positions in the trans isomer
In trans-1,2-dimethylcyclohexane, the diequatorial conformation places both bulky methyl groups in equatorial orientations, avoiding 1,3-diaxial steric repulsions. In the cis isomer, one methyl group must always be axial (axial-equatorial).
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