Diastereomer Method for Determining ee by 1H NMR and/or MS Spectrometry with Complete Removal of the Kinetic Resolution Effect

Abstract
Using chiral auxiliaries, 2-methoxy-2-(1-naphthyl)propionic acid (MαNP acid) (S)-(+)-1 and its deuterium-labeled enantiomer (R)-(−)-1-dn (n = 3 or 6), we have developed a new diastereomer method for determining enantiomeric excess (% ee) of chiral alcohols by 1H NMR and/or MS spectrometry, where the kinetic resolution effect is completely excluded. The data of % ee determined by this method agree well with those calculated by weight, the average error being ca. ±1.08% ee.