- Synthesis of Condensed Tannins. Part 2. Synthesis by Photolytic Rearrangement, Stereochemistry, and Circular Dichroism of the First 2,3-cis,3,4-cis-4-Arylflavan-3-ols
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Photolytic rearrangements of those 2,3-trans-3,4-trans- and 2,3-trans-3,4-cis-4-arylflavan-3-ols in which the nucleophilicity of D-ring (4-aryl group) functionality exceeds that of the A-ring, provide the first access to 2,3-cis-3,4-cis-diastereoisomers.The circular dichroism of these new isomers is at variance with the proposed general rule for assessing the absolute configuration at C-4.In terms of the aromatic quadrant rule such discrepancies correlate with deviations from the preferred C-ring conformations.
- Westhuizen, Jan H. van der,Ferreira, Daneel,Roux, David G.
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p. 1220 - 1226
(2007/10/02)
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