COUMARIN-CONTAINING CHIRAL DISCRIMINATING AGENTS .7. NEW CRYSTALLINE H-1-NMR ENANTIOMERIC EXCESS DETERMINATION REAGENT FOR ALCOHOLS AND AMINES, (R)-(-)-O-COUMARINYLMANDELIC AND (S)-(-O-COUMARINYLMANDELIC ACIDS())

The Mitsunobu reaction of commercial 4-hydroxycoumarin with both (R)(- )- and (S)-(+)-tert-butyl mandelates derived from commercial enantiopu re mandelic acids furnished (S)-(+)- and (R)-(-)-tert-butyl O-coumarin ylmandelates which were, then, treated with trifluoroacetic acid to gi ve novel crystalline optically pure (S)-(+)- and (R)-(-)-O-coumarinylm andelic acids [SCMOH and RCMOH], respectively in good overall yields. Diastereotopic nonequivalence H-1-NMR examination of the resultant est ers and amides without any racemization or kinetic resolution by way o f a Steglich's procedure (a DCC-DMAP method) has proved each acid to b e a useful, efficient and reliable chiral derivatizing agent for the e nantiomeric excess determination of chiral alcohols and amines.