Abstract: The invention relates to a novel process for the preparation of C-4 coupled flavonoids, proanthocyanidins and analogues thereof. According to a specific application of the invention, there is provided a method for the preparation of proanthocyanidins and proanthocyanidin analogues.

Abstract: The invention relates to methods for the preparation of an optically inactive and optically active compounds which are selected from the group consisting of C-3 coupled biflavonoids and C-3 coupled biflavonoid analogues from a starting material or intermediate which are respectively selected from the group consisting of optically inactive or optically active flavan-3-ols and optically active flavan-3-ones, the method comprising the steps of (a) providing an optically inactive or active compound having a flavan-3-ol structure or a compound which is a flavan-3-one, (b) if a compound having a flavan-3-ol structure with a hydroxy group on the C-3 carbon is selected as starting material, converting the hydroxy group on the C-3 carbon of the compound having the flavan-3-ol structure to an oxo group to form a flavan-3-one of that compound, (c) providing a compound having a nucleophilic aromatic moiety, which compound is selected from the group of compounds having a nucleophilic aromatic moiety and which have flavono