Wittig‐Type Olefination of Alcohols Promoted by Nickel Nanoparticles: Synthesis of Polymethoxylated and Polyhydroxylated Stilbenes

Nickel nanoparticles were found to promote the Wittig‐type olefination of primary alcohols with phosphorus ylides. The latter can be prepared from the corresponding phosphonium salts with n BuLi or in situ generated with lithium metal. The methodology is especially efficient for the synthesis of stilbenes and is applied in the absence of any additive as ahydrogen acceptor. A new approach to the synthesis of polymethoxylated and polyhydroxylated stilbenes, including resveratrol, DMU‐212 and analogues, is presented.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)