58065-34-2

Upstream product

• 108-24-7 acetic anhydride 
• 51196-02-2 5,7,3',4'-tetra-O-methylepicatechin 
• 190381-24-9 (1R,2R)-3-(2,4-Dimethoxy-6-methoxymethoxy-phenyl)-1-(3,4-dimethoxy-phenyl)-propane-1,2-diol 
• 6563-36-6 (2R^*,3S^*,4R^*)-flavan-3,4-diol 
• 19611-22-4 (+/-)-3',4',5,7-tetra-O-methylcatechin 
• 16198-01-9 (+/-)-pentaacetylcatechin 
• 490-46-0 (2R,3R)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-1[2H]-benzopyran-3,5,7-triol 
• 190381-22-7 (E)-1-(3,4-dimethoxyphenyl)-3-(2-methoxy-methyl-4,6-dimethoxy-phenyl)-propene 

Downstream Products

• 25095-07-2 4β-methoxy-tetra-O-methyl-3-O-acetyl-(-)-epicatechin 
• 25095-07-2 (+/-)-2,3-cis-3,4-trans-4,5,7,3',4'-Pentamethoxy-flavanol-3-acetat 

Relevant academic research and scientific papers

Enantioselective synthesis of flavonoids. Part 3. trans- and cis-flavan-3-ol methyl ether acetates

Asymmetric dihydroxylation of a series of polyoxygenated 1,3-diarylpropenes with AD-mix-α or AD-mix-β in the presence of methanesulfonamide and subsequent acid-catalysed cyclization, affords for the first time synthetic access to trans- and cis-flavan-3-ol derivatives, essentially enantiopure and in good yield.

Enantiomers synthesis of the four catechin diastereomer derivatives

Asymmetric dihidroxylalion of (E)-1 -(3,4-dimethoxyphenyl)-3-2-methoxy-methyl-4,6- dimethoxy-phenyl)-propene with AD-mix-α or AD-mix-β in the presence of methanesulfonamide, followed by acid catalysed cyclization, afforded the four catechin diastereomers in high enantiomeric excesses and yields.

Oligomeric flavanoids. Part 19. Reductive cleavage of the interflavanyl bond in proanthocyanidins

The interflavanyl bond in profisetinidins 1, 4 and 6, and methyl ethers 3, 5, 28 and 29 procyanidins 24 and 26, and their methyl ethers 25 and 27 is readily subject to cleavage with sodium cyanoboranuide in trifluoroacetic acid at 0 deg C.This method will contribute significantly to the structure elucidation of the 5-deoxy (A-ring) proanthocyanidins from important commercial sources.Boltzmann-averaged heterocyclic ring coupling constants as determined by a conformational global search routine (GMMX) and NOE difference spectroscopy were used to assign unequivocally the diastereotopic methylene protons in the 1H NMR spectra of flavan-3-ols, a prerequisite for corroboration of the cleavage mechanism.

Oligomeric Flavonoids. Part 16. Novel Prorobinetinidins and the First A-Type Proanthocyanidin with a 5-Deoxy A- and 3,4-cis-C-Ring from the Maiden Investigation of Commercial Wattle Bark Extract

Structural examination of the phenolic metabolites of commercially used wattle bark extract reveals the presence of a range of novel flavonoids comprising (-)-epirobinetinidol 1, the first C-methyl proanthocyanidin, (-)-fisetinidol-(4α,8)-6-methyl-(+)-catechin 3, the first prorobinetinidins with 3,4-cis-C-ring configurations 7 and 9, and the unique A-type prorobinetinidin 11 representing the first entry amongst this class of oligoflavonoids exhibiting a 5-deoxy A- and a 3,4-cis-C-ring.They are accompanied by a range of functionalized prorobinetinidin-type tetrahydropyranochromenes 20, 23, 25 and 28 and the trimeric 'isomerization-intermediate' 32, all exhibiting the characteristic structural features that are essential for the use of 'Mimosa' exctract in cold-setting adhesives and leather-tanning applications.In addition, evidence demonstrating that the dynamic A-E conformational equilibrium of flavan-3-ol moieties in condenced tannins may be influenced by external factors is presented.

Proton magnetic resonance spectra of catechin and bromocatechin derivatives: C6- vs. C8-substitution

The 1Hmr spectra of 20 catechin derivatives substituted at C-6/C-8 by bromine and/or hydrogen and at oxygen by methyl, acetyl, and/or hydrogen have been analyzed in deuterated acetone, acetonitrile, and chloroform.Because of its dependence on the nature o