¹⁸O-Labeled chiral compounds enable the facile determination of enantioselectivity by mass spectroscopy

The synthesis of O-18-labeled enantioenriched compounds and their facile evaluation system to determine enantiomeric excess (ee) using mass spectroscopy was described. Equimolar mixture of O-18-labeled and non-labeled pseudo-enantiomers were used as a substrate for enzyme-catalyzed kinetic resolution. Ees determined by mass spectroscopy showed good agreement with those by HPLC. Our method would be a promising tool for fast evaluation of ee and contribute to development of enantioselective transformations. (C) 2019 Published by Elsevier Ltd.