Patent ID: 7820848

Claim:
A process for the preparation of resveratrol or piceatannol, or an ester of either, which process comprises reacting, in about equimolar amounts and under Heck reaction conditions, a compound of formula I with a compound of formula II wherein Z and Z 1 is each, independently, a protected hydroxy group; Z 2 is hydrogen or a protected hydroxy group; and one of A and B is vinyl and the other is chloro or bromo; to obtain a compound of formula III wherein Z and Z 1 are as defined above, and R 1 is hydrogen or a protected hydroxy group; then cleaving the hydroxy protecting groups from the compound of formula III under basic or substantially neutral hydrolysis to obtain resveratrol or piceatannol, and, optionally, converting the so-obtained resveratrol or piceatannol into an ester thereof, and, optionally, isomerizing (E)-resveratrol or ester thereof or (E)-piceatannol or ester thereof to obtain the corresponding (Z)-isomer.