Ranking the effect of [1A(ax), 1B(eq)] versus [1A(eq), 1B(ax)] cyclohexane ring substitution on the 1H chemical shifts of γ-methylene cyclohexane ring protons using 2,2-disubstituted adamantanes as models

The 1H chemical shift separation at 298 K within 4′,9′-H and 8′,10′-H methylenes was compared for different pairs of substituents A, B in various 2,2-disubstituted adamantanes. This provides an accessible protocol to compare the effect of [1A(ax), 1B(eq)] and [1A(eq), 1B(ax)] substitution on the 1H resonance separation within cyclohexane ring γ-CH2 protons.