478796-18-8

Upstream product

• 20728-73-8 5,7,3',4'-tetra-O-benzyl-(+)-catechin 
• 108-24-7 acetic anhydride 

Downstream Products

• 664351-48-8 [4,8']-2,3-trans-3,4-trans:2',3'-cis-octa-O-benzyl-3-O-acetyl-(+)-catechin-(-)-epicatechin 
• 476312-06-8 [4,8']-2,3-trans-3,4-trans:2',3'-trans-octa-O-benzyl-3-O-acetyl-bi-(+)-catechin 

Relevant academic research and scientific papers

Synthesis of procyanidin B1, B2, and B4 and their anti-inflammatory activity: The effect of 4-alkoxy group of catechin and/or epicatechin electrophiles for condensation

Abstract: Procyanidin B1, B2, and B3 were synthesized based on a Yb(OTf)3 catalyzed equimolar condensation using methoxy and/or 4-(2-ethoxyethoxy) drivatives as electrophiles. The anti-inflammatory effect of synthetic procyanidin B1, B2, and B4 on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation of mouse ears was examined. Procyanidin B1, B2, B 4 suppressed TPA-induced inflammation of mouse ears by 48%, 34%, and 29%, respectively, at a dose of 200 μg. Their activities are stronger than those of indomethacin and glycyrrhetinic acid, the normally used antiinflammatory agent.

Synthetic studies of proanthocyanidins. Part 2: Stereoselective gram-scale synthesis of procyanidin-B3

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.