[EN] METHOD FOR THE PREPARATION OF C-4 COUPLED FLAVONOIDS, PROANTHOCYANIDINS AND ANALOGUES THEREOF [FR] PROCÉDÉ DE PRÉPARATION DE FLAVONOÏDES COUPLÉS EN C-4, DE PROANTHOCYANIDINES ET D'ANALOGUES CORRESPONDANTS
[EN] METHOD FOR THE PREPARATION OF C-4 COUPLED FLAVONOIDS, PROANTHOCYANIDINS AND ANALOGUES THEREOF<br/>[FR] PROCÉDÉ DE PRÉPARATION DE FLAVONOÏDES COUPLÉS EN C-4, DE PROANTHOCYANIDINES ET D'ANALOGUES CORRESPONDANTS
申请人:UNIV FREE STATE ZA
公开号:WO2009147645A1
公开(公告)日:2009-12-10
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.
Synthesis of Proanthocyanidins. Part 1. The First Oxidative Formation of the Interflavanyl Bond in Procyanidins
作者:Matthew C. Achilonu、Susan L. Bonnet、Jan H. van der Westhuizen
DOI:10.1021/ol801353u
日期:2008.9.1
A novel and efficient method for the oxidative condensation of tetra-O-methyl-3-oxocatech in 4 with tetra-O-methylcatechin is described. Treatment of a solution of 3 (2 equiv) and 4 (1 equiv) with silver tetrafluoroborate readily affords the phenolic per-O-methyl ethers of 3-oxocatechin(4-8)-catechin 18 and 19. Subsequent metal hydride reduction provides access to procyanidin B-3 analogues with the 3,4-cis diastereomers predominating.