 their ^0^H NMR spectra ([Fig. 0d](#f0){ref-type="fig"} and [Supplementary Fig. 00](#S0){ref-type="supplementary-material"}), all of the amide NH resonances of (*R*,*R*,*S*,*S*,*R*,*R*)-**0b**·(*S*,*S*)-**0a** 