FORMATION OF CHIRAL 4-CHROMANONES USING CHIRAL PYRROLIDINES IN THE PRESENCE OF UREAS OR THIOUREAS

摘要

The present invention relates to a synthesis of chromanones or chromanes in a stereospecific matter in view of the 2-position in the chromanone or chromane ring. It has been found that this synthesis is particularly possible in the presence of a chiral compound of formula of a specific type and of at least one urea or thiourea.