摘要 |
<p>The present invention relates to a method of reacting (3R,3'R,6'R)-lutein with a catalytic amount of an acid to obtain a mixture of anhydroluteins, rich in anhydrolutein III, with substantially no Z-isomers being formed. The mixture is converted to (3R)-β-cryptoxanthin (major product) and (3R,6'R)-α-cryptoxanthin (minor product) by reacting the anhydroluteins with borane-amine complexes (e.g. Me3N.BH3) or other hydride donors and an acid in a chlorinated solvent, preferably dichloromethane, at ambient temperature to produce (3R)-β-cryptoxanthin and (3R,6'R)-α-cryptoxanthin.</p> |