A total synthesis of verbenachalcone, a bioactive diaryl ether from Verbena littoralis

Verbenachalcone 1, isolated from the aerial part of Verbena littoralis H. B. K. (Verbenaceae) has successfully been synthesized by employing anodic oxidation of the phenol derivative 3, as the key step. The bromine and chlorine substituents of 3 effected regioselective of a methoxy group, as well as modulating the oxidation reaction. A flow-cell type apparatus of anodic oxidation provided the desired diaryl ether 4 in good yield. (C) 2004 Elsevier Ltd. All rights reserved.