That allylic position is tough to work with;
. When we examine the C-1 to C-2 bond, we see that the methyl group is at a 60° dihedral angle to C-3. A similar relationship exists between the methyl group and C-5 when the view is along the C-1 to C-6 bond. In the equatorial conformation, the methyl group is anti to both C-3 and C-5. Therefore, the steric strain for the axial conformation of methylcyclohexane is twice that of the gauche interaction of butane or 2 × 3.8 = 7.6 kJ mole− 1.