97233-66-4

Upstream product

• 480-17-1 2,3-trans-flavan-3,4-diol 
• 490-46-0 (2R,3R)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-1[2H]-benzopyran-3,5,7-triol 
• 37064-35-0 4β-benzylthioepicatechin 
• 154-23-4 catechin 
• 22970-70-3 (2R,3R,4S)-2,3-cis-3,4-trans-3',4',5,7-tetramethoxyflavan-3,4-diol 

Downstream Products

• 13306-05-3 cyanidin 
• 25664-00-0 epicatechin-(4β->8)-epicatechin-(4β->8)-catechin-peracetate 
• 37064-35-0 4β-benzylthioepicatechin 
• 68200-27-1 (2R,3R,4R)-2,3-cis-3,4-trans-3,5,7,3',4'-pentahydroxy-4-<(2R,3S,4S)-2,3-cis-3,4-trans-3,5,7,3',4'-pentahydroxy-4-benzylthioflavan-8-yl>flavan 
• 128900-23-2 Epicatechin-(4β->8)-4α-benzylthioepicatechin 
• 128837-34-3 4α-Benzylthioepicatechin 
• 154-23-4 catechin 
• 20315-25-7 procyanidin B₁ 

Relevant academic research and scientific papers

Oligomeric flavanoids. Part 27. Interflavanyl bond formation in procyanidins under neutral conditions

Dimethyl(methylthio)sulfonium tetrafluoroborate (DMTSF) and silver tetrafluoroborate (AgBF4) activate the C4-S bond in the 4-thioethers of flavan-3-ols toward carbon nucleophiles to permit formation of the interflavanyl bond in procyanidins under neutral conditions.

SYNTHESIS AND CHARACTERIZATION OF PROCYANIDIN DIMERS AS THEIR PERACETATES AND OCTAMETHYL ETHER DIACETATES

Key Word Index - Biomimetic synthesis; procyanidins B1-B8; 3,4-cis-biflavanoid; all--bi--(+)-catechin; 1H NMR parameters. Condensation of (2R,3S,4R or S)-leucocyanidin or the 5,7,3',4'-tetramethyl ether of (2R,3R,4S)-leucocyanidin with flavan-3-ols yielded dimeric flavanoids which were converted to their octamethyl ether diacetates, or the deca-acetates for the 2,3-trans-procyanidin series.Comparison is made of the 1H NMR spectra of the deca-acetate and octamethyl ether diacetate derivatives which lead to useful diagnostic shift parameters characteristic of their structures.Condensation afforded a novel biflavanoid with a 3,4-cis-configuration and a triflavanoid of 'mixed' stereochemistry.

Synthesis of Condensed Tannins. Part 13. The First 2,3-trans-3,4-cis-Procyanidins: Sequence of Units in a 'Trimer' of Mixed Stereochemistry

The condensation of (+)-leucocyanidin with (-)-epicatechin initiates a succession of substitutions leading mainly to the introduction of -2,3-trans-3,4-procyanidin units, but also to the incorporation of 'terminal' moieties which possess the hitherto unique 3,4-cis-procyanidin configuration.The bonding patterns in the products, and also the sequence of units in one of the 'trimers' of mixed stereochemistry, are resolved by (1)H n.m.r. spectroscopy through selective use of solvents at elevated temperatures.