125136-18-7

Upstream product

• 125090-60-0 (2S,3R,4S)-4α-(2,4,6-trihydroxyphenyl)flavan-3,3',4',7-tetraol 
• 69082-77-5 (2R,3S,4S)-2,3-trans-3,4-trans-4-(2,4,6-trihydroxyphenyl)flavan-3,3',4',7-tetraol 

Downstream Products

• 528-58-5 cyanidin chloride 
• 2948-76-7 fisetinidin chloride 
• 125090-71-3 Acetic acid (2R,3R,4S)-4-(2,4-dimethoxy-phenyl)-2-(3,4-dimethoxy-phenyl)-5,7-dimethoxy-chroman-3-yl ester 
• 78174-76-2 2,3-cis-3,4-cis-3',4',5,7-tetramethoxy-4-(2,4-dimethoxyphenyl)flavan-3-ol 

Relevant academic research and scientific papers

OLIGOMERIC FLAVANOIDS.PART 6.EVIDENCE SUPPORTING THE INVERSION OF ABSOLUTE CONFIGURATION AT 3-C ASSOCIATED WITH BASE CATALYSED A-/B-RING INTERCHANGE OF PRECURSORS HAVING 2,3-TRANS-3,4-CIS-FLAVAN-3-OL CONSTITUENT UNITS

Whereas the enantiomeric 2,3-trans-3,4-trans-arylflavan-3-ols (10) and (12) as biflavanoid models are subject to stereospecific C-ring isomerisation under base catalysis, those with 3,4-cis configuration (11) and (13) are transformed stereoselectively via

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

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.