Patent ID: 8093436

Claim:
A process for converting (3R)-3′,4′-anhydrolutein to a mixture of (3R,3′R)-zeaxanthin and (3R,3′S;meso)-zeaxanthin by regioselective hydroboration comprising reacting (3R)-3′,4′-anhydrolutein with a hydroborating reagent, in a solvent, at a temperature ranging from 0-30° C. to obtain an isomeric mixture of (3R,3′R)-zeaxanthin and (3R,3′S;meso)-zeaxanthin as major products, in a ratio ranging from 1:1 to 3.4:1 and a-cryptoxanthin and (3R,4′RS)-β,β-caroten-3,4′-diol as two minor products.