69119-50-2Relevant academic research and scientific papers
Regio- and stereoselective oxidation of flavan-3-ol-, 4-arylflavan-3-ol-, and biflavanoid derivatives with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)
Steenkamp,Mouton,Ferreira
, p. 6705 - 6716 (2007/10/02)
The phenolic methyl esthers of flavan-3-ols, 4β-arylflavan-3-ols, and (-)-fisetinidol-(4β,8)-(+)-catechin biflavanoids are susceptible to regio- and stereoselective methoxylation at C-4 in moderate yields with DDQ in CHCl3-MeOH solution. The observed asymmetric induction with exclusive formation of 2,4-trans products is compatible with the intermediacy of a diastereogenic donor-acceptor interaction, DDQ acting as the acceptor and oxidant. The 4-funtionalized analogues are of both synthetic and degradative significance in condensed tannin chemistry.
Proton magnetic resonance spectra of catechin and bromocatechin derivatives: C6- vs. C8-substitution
Kiehlmann, E.,Tracey, A. S.
, p. 1998 - 2005 (2007/10/02)
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
STEREOSPECIFIC FUNCTIONALIZATION OF THE HETEROCYCLIC RING SYSTEMS OF FLAVAN-3-OL AND -BIFLAVAN-3-OL DERIVATIVES WITH 2,3-DICHLORO-5,6-DICYANO-1,4-BENZOQUINONE (DDQ)
Steenkamp, Jacobus A.,Ferreira, Daneel,Roux, David G.
, p. 3045 - 3048 (2007/10/02)
Efficient stereospecific 4-methoxylation of both 2,3-trans- and 2,3-cis-flavan-3-ol methyl ethers with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in CHCL3-MeOH solution is of both synthetic and degradative significance in oligomeric flavanoid chemist
Synthesis of Condensed Tannins. Part 12. Direct Access to - and -all-2,3-cis-Procyanidin Derivatives from (-)-Epicatechin: Assessment of Bonding Positions in Oligomeric Analogues from Crataegus oxyacantha L.
Kolodziej, Herbert,Ferreira, Daneel,Roux, David G.
, p. 343 - 350 (2007/10/02)
Synthesis of methyl ester acetates of - and -all-2,3-cis-procyanidin biflavanoids is effected by oxidative functionalization of (-)-epicatechin tetramethyl ester with lead tetra-acetate, and condensation of the resultant 2,3-cis-flavan-3,4-diol
Synthesis of Condensed Tannins. Part 3. Chemical Shifts for Determining the 6- and 8-Bonding Positions of 'Terminal' (+)-Catechin Units
Hundt, Hans K. L.,Roux, David G.
, p. 1227 - 1234 (2007/10/02)
Pairs of 6- and 8-functionalised (Br, OH, OAc, CO2Me, and CH2Me groups) 3',4',5,7-tetra-O-methyl-(+)-catechins available through selective bromination and debromination reactions and hence via lithio-analogues, provide diagnostic chemical shifts of their
