3,5-bis(trifluoromethyl)phenyl sulfones in the modified Julia olefination:: application to the synthesis of resveratrol

The reaction between carbanions derived from alkyl 3,5-bis(trifluoromethyl)phenyl sulfones and aldehydes, affords with good yields and stereoselectivities the corresponding 1,2-disubstituted alkenes through the Julia-Kocienski olefination reaction. This one-pot protocol can be performed using KOH at room temperature or the phosphazene base P4-t-Bu at -78 degreesC, and has been successfully used in a high yielding and stereoselective synthesis of various stilbenes such as resveratrol. (C) 2003 Elsevier Ltd. All rights reserved.