Synthesis of Piceatannol, an Oxygenated Analog of Resveratrol.

Piceatannol (3,3',4,5'-tetrahydroxy-trans-stilbene, 2), an oxygenated analog of resveratrol (1), was synthesized. It is one of the naturally occurring polyphenolic stilbenoids contained in red wine, and possesses many kinds of beneficial effects such as anticancer activity. The trans-stilbene skeleton of 2 was constructed by Pd-catalyzed Suzuki-Miyaura cross coupling reaction of triflate 8 with (E)-alkenylboronoate 13. The key intermediate 13 was prepared diastereoselectively by acid-catalyzed hydroboration of pinacolborane 12 to alkyne 11.