Oxyresveratrol and its methylated derivative as coupling precursors were efficiently
prepared in four steps, with Wittig reactions and subsequent isomerization reactions
as the key steps. The coupling reactions of oxyresveratrol under various oxidative
conditions gave a complex and inseparable mixture of coupling products. The oxidative
dimerizations of methylated oxyresveratrols catalyzed by horseradish peroxidase–H2O2 or FeCl3·6H2O in an acetone system predominantly produced the 8–5-coupled and 8–10-coupled dihydrobenzofuran-type
dimers, respectively. This regioselective biomimetic strategy might be useful in synthesizing
other dimeric oxyresveratrol derivatives.
Key words
oxyresveratrol - biomimetic synthesis - oligostilbenes - oxidative coupling - dimerization
- regioselectivity