111421-89-7Relevant academic research and scientific papers
Condensed Tannins: Base-Catalysed Reactions of Polymeric Procyanidins with Toluene-α-thiol. Lability of the Interflavanoid Bond and Pyran Ring.
Laks, Peter E.,Hemingway, Richard W.
, p. 465 - 470 (2007/10/02)
Reaction of polymeric procyanidins (condensed tannins) with toluene-α-thiol at pH 12.0 and 23 degC gave predominantly one stereoisomer of 1,3-bisbenzylthio-1-(3,4-dihydroxyphenyl)-3-(2,4,6-trihydroxyphenyl)propan-2-ol (10) by stereoselective reaction at C-4 and C-2 of the quinone methide derived from the upper 2,3-cis procyanidin units.Smaller amounts of two isomers of 1-benzylthio-1-(3,4-dihydroxyphenyl)-3-(2,4,6-trihydroxyphenyl)propan-2-ol (4) were obtained by reaction at the C-2 of catechin obtained from the terminal units.At higher temperatures, (10) loses toluen-α-thiol preferentially from C-1 to give 1-benzylthio-1-(3,4-dihydroxyphenyl)-3-(2,4,6-trihydroxyphenyl)-propan-2-one (11) by a tautomeric rearrangement of the quinone methide via an enol to the keton.Loss of toluene-α-thiol from (4) gave 1-(3,4-dihydroxyphenyl)-3-(2,4,6-trihydroxyphenyl)propan-2-one (5) by a similar rearrangement.This compound further rearranges to 1-(3,4-dihydroxyphenyl)-4,6-dihydroxyindan-2-one (6).
