2004/01/01 by Akiko Saito, Noriyuki Nakajima, Akira Tanaka +1 · 3 citations
Pharmacology, Toxicology and Pharmaceutics · Medicine · Chemistry · #Bioactive Compounds and Antitumor Agents #Morinda citrifolia extract uses #Oxidative Organic Chemistry Reactions
paper · doi:10.1055/s-2004-822905
openalex publication_date 2004/01/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/11
A stereoselective synthesis of seven benzylated proanthocyanidin trimers with TMSOTf-catalyzed condensation reaction is described. In particular, epicatechin-(4β-8)-epicatechin-(4β-8)-epicatechin trimer (procyanidin C1), catechin-(4α-8)-catechin-(4α-8)-catechin trimer (procyanidin C2), epicatechin-(4β-8)-epicatechin-(4β-8)-catechin trimer and epicatechin-(4β-8)-catechin-(4α-8)-epicatechin trimer derivatives were obtained in excellent yields. The structure of benzylated procyanidin C2 was confirmed by comparing the 1H NMR spectra of protected procyanidin C2 that was synthesized by two different condensation approaches. Finally, deprotection of (+)-catechin and (-)-epicatechin trimers derivatives gave four natural procyanidin trimers in good yields.