New macrocyclic compound as chiral shift reagent for carboxylic acids

We have prepared a novel chiral macrocyclic compound 3 from a C-2-symmetric aminonaphthol in a high yield. Enantiomeric acids have large nonequivalent chemical shifts (up to 0.80 ppm) in the presence of 3 in H-1 NMR (500 MHz) spectra. Quantitative analyses of a series of mandelic acids with different enantiomeric purities show that host 3 is an excellent chemical shift reagent for chiral carboxylic acids.