478796-23-5Relevant academic research and scientific papers
Synthetic studies of proanthocyanidins. Part 2: Stereoselective gram-scale synthesis of procyanidin-B3
Saito, Akiko,Nakajima, Noriyuki,Tanaka, Akira,Ubukata, Makoto
, p. 7829 - 7837 (2007/10/03)
A stereoselective synthesis of procyanidin-B3, a condensed catechin dimer, is described. Condensation of benzylated catechin with various 4-O-alkylated flavan-3,4-diol derivatives as an electrophile in the presence of a Lewis acid led to protected procyanidin-B3 and its diastereomer. In particular, the reaction using (2R,3S,4S)-3-acetoxy-5,7,3′,4′-tetrabenzyloxy-4-(2″- ethoxyethoxy)flavan as an electrophile in the presence of TMSOTf at -78°C afforded octa-O-benzylated procyanidin-B3 with high levels of stereoselectivity and in excellent isolation yields. Furthermore, we succeeded in a stereoselective gram-scale synthesis of protected procyanidin-B3.
