Calibration plots to aid determination of high enantiomeric purity using chiral lanthanide shift reagents.

High enantiomeric purities are difficult to determine by NMR with chiral lanthanide shift reagents because it is difficult to identify which, if any, resonance corresponds to the minor enantiomer. We report calibration plots that use the position of the resonance of the major enantiomer to predict the position of the resonance of the minor enantiomer. Once the position of the resonance was established, integration measured enantiomeric purities as high as 99.7% ee.