What is the difference in energy between the two chair conformations of cis-1,4-dimethylcyclohexane? Cis-1,4-substitution in a chair cyclohexane means that one group (methyl) must be equatorial and the other axial [Review]. The left hand structure has an axial blue methyl group and the an equatorial red methyl group. A chair-chair interconversion merely switches the position of the two groups: equatorial ---> axial; axial ---> equatorial. The right hand structure has a red axial methyl group and a blue equatorial methyl group. Therefore, ΔG^o = 0 kcal/mol and K_eq = 1 for the two chair conformations. The total energy for each chair conformation is 1.8 kcal/mol.