Asymmetric epoxidation catalyzed by D-glucose-derived uloses

Three ulose catalysts (1-3) were prepared from D-glucose via an intramolecular nitrile oxide cycloaddition (INOC) as the key step. The enantioselectivity of ulose 2 and 3 in asymmetric epoxidation was poor (up to 26% ee). Ulose 1 afforded good chemical yields (up to 83% yield) and the enantiomeric excess is up to 71% for the formation of (-)-trans-stilbene oxide. (C) 2002 Elsevier Science Ltd. All rights reserved.