Condensed tannins. 16. Synthesis of (−)-flavans from (+)-dihydroflavonols
- 1 May 1963
- journal article
- research article
- Published by Portland Press Ltd. in Biochemical Journal
- Vol. 87 (2), 435-439
- https://doi.org/10.1042/bj0870435
Abstract
The absolute configurations [both (2S)] of (-)-3[image],4[image], 5[image], 7-tetrahydroxyflavan and ([long dash])-3[image], 4[image], 7-trihydroxyflavan were established by interconversions from dihydroflavanols and flavanones of known configuration. The contributions to the molecular rotations of some flavan and flavanone analogues at each of the asymmetric centers C-2, C-3 and C-4 were determined. These appear to be additive for flavan analogues of the 3[image], 4[image], 5[image], 7 and 3[image], 4[image], 7 patterns of phenolic hydroxylation. This knowledge might assist in predicting the absolute configuration of analogues of the same series. Proof has been provided that the 4-hydroxyl group is mainly contributory to the redness induced in flavonoid compounds by sunlight.This publication has 8 references indexed in Scilit:
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