Metabolites from the purple heartwoods of the mimosoideae. Part 4. Acacia fasciculifera F. Muell ex. Benth: fasciculiferin, fasciculiferol, and the synthesis of 7-aryl- and 7-flavanyl-peltogynoids

Abstract

Structural examination of the heartwood metabolites of Acacia fasciculifera revealed the presence of fasciculiferin, a novel peltogynoid, and fasciculiferol, a dibenzo-α-pyrone, in addition to known flavonoids, peltogynoids, and biflavanoids.

Synthesis of 7-aryl- and 7-flavanyl-peltogynoids as model tannins from peltogynol requires increasingly drastic conditions with decrease of nucleophilicity of the substrate. These condensations come progressively under thermodynamic control and proceed with greater difficulty than those involving the flavan-3,4-diol analogue.