[TABLE 3-6] shows that the axial–equatorial energy difference for methyl, ethyl, and isopropyl groups increases gradually: 7.6, 7.9, and 8.8 kJ/mol (1.8, 1.9, and 2.1 kcal/mol). The tert-butyl group jumps to an energy difference of 23 kJ/mol (5.4 kcal/mol), over twice the value for the isopropyl group.
1. Draw pictures of the axial conformations of isopropylcyclohexane and tert-butylcyclohexane
2. Explain why the tert-butyl substituent experiences such a large increase in axial energy over the isopropyl group.