 (for details, see [Supplementary Methods](#S0){ref-type="supplementary-material"}). (**c**) ^0^H NMR spectra of carboxylic acid CO~0~H and amide NH proton resonances of **0a** (0.00 mM) with different % e.e. in CDCl~0~ at 00 °C. Full-scale spectra are shown in [Supplementary Fig. 00b](#S0){ref-type="supplementary-material"}. (**d**) Partial ^0^H NMR spectra (0.0