Fig. 4. (a) Statistical permutations of configuration and conformation for [2 + 3] amide cages formed with an unsymmetric bisaldehyde. (b) Synthesis of cage 3e confirms the expected configuration and conformation according to the geometry heuristics discussed above. (c) 1H-NMR data (CDCl3) demonstrating the chemical shift effects of localised carbonyl orientation differences in cage 3e.
