The all-trans-1,2,3,4,5,6-hexaethylcyclohexane ( 1) prefers the all-equatorial conformation while the all-trans-1,2,3,4,5,6-hexaisopropylcyclohexane (2) possesses a severely destabilized all-equatorial conformation (J. Am. Chem. Soc. 1990, 112, 893–894):
(b) The all-axial conformation of 2 possesses a fairly stable conformation where the steric repulsion among the axial isopropyl groups can be minimized. Again, use models to examine this chair conformation and draw it. Also, draw a Newman projection looking down one of the C—C bonds connecting the cyclohexyl ring to an axial isopropyl group and illustrate why this conformation is lower than the all-equatorial chair conformation in steric destabilization.