105880-86-2Relevant academic research and scientific papers
Oligomeric Flavanoids. Part 11. Structure and Synthesis of the First Phlobatannins Related to (4α,6:4α,8)-Bis-fisetinidol-(+)-catechin Profisetinidin Triflavanoids
Steynberg, Jan P.,Steenkamp, Jacobus A.,Burger, Johann F. W.,Young, Desmond A.,Ferreira, Daneel
, p. 235 - 240 (2007/10/02)
Several members of the unique class of natural phlobatannins, representing the products of stereospecific pyran rearrangement of 2,3-trans-3,4-trans-flavan-3-ol units present in, e.g., (4α,6:4α,8)-bis-(-)-fisetinidol-(+)-catechin triflavanoid profisetinidins, have been characterized.These include the functionalized 6,7-trans-7,8-cis-10,11-trans-11,12-cis-hexahydrodipyranochromene (3) and the 10-flavanyl-6,7-trans-7,8-cis-tetrahydropyranochromene 'isomerisation-intermediates' (6), (15), and (17).The proposed structures of compounds (3) and (6) were confirmed by synthesis via base-catalysed conversion of the 3-O(E)-methyl ether (1) of its apparent biogenetic precursor, and the relative nucleophilicity of the A- and D-ring in the 'dimeric' tetrahydropyranochromene (14) assessed by condensation with the flavan-3,4-diol, (+)-mollisacacidin.
Phlobatannins via Facile Ring Isomerizations of Profisetinidin and Prorobinetinidin Condensed Tannin Units
Steynberg, Jan P.,Young, Desmond A.,Burger, Johann F. W.,Ferreira, Daneel,Roux, David G.
, p. 1013 - 1015 (2007/10/02)
-2,3-trans-3,4-trans-(-)-Fisetinidol-2,3-trans-(+)-catechin and its (-)-robinetinidol homologue are to a varying degree subject to facile ring isomerizations (also when preceded by induced positional isomerization) in NaHCO3-Na2CO3 buffer solution un
