Diaxial interaction

Diaxial or 1,3-diaxial interactions are steric interactions between two axial groups on a cyclohexane ring. These steric interactions are responsible for the higher energy of conformations with axial substituents relative to equatorial substituents. In methylcyclohexane, there are two 1,3-diaxial interactions costing 0.9 kcal/mol each for a total of 1.8 kcal/mol.