Total syntheses of wyerone and dihydrowyerone, phytoalexins from the broad bean, Vicia faba L., using the dianion derived from 3-(2-furyl)acrylic acid

Abstract

Treatment of 3-(2-furyl)acrylic acid (8) with lithium di-isopropylamide at low temperatures gives lithium 3-(5-lithio-2-furyl)acrylate (9). This has been used to prepare the broad bean metabolites wyerone (1) and dihydro-wyerone (2) by condensations with (Z)-hept-4-en-2-ynal (13) and hept-2-ynal (11), respectively, followed by esterification and oxidation.