Synthesis of condensed tannis. Part 8. The first ‘Branched’[4,6 : 4,8 : 4,6]-tetraflavanoid. Coupling sequence and absolute configuration
作者:Jacobus A. Steenkamp、Daneel Ferreira、David G. Roux、William E. Hull
DOI:10.1039/p19830000023
日期:——
3-trans-flavan-3,3′,4′,7-tetraol [(–)-fisetinidol] proceeds beyond the expected biflavanoid range to generate significant yields of both the ‘linear’[4,6 : 4,6]-2,3-trans-3,4-cis : 2′,3′-trans-3′,4′-trans : 2″,3″-trans-trifisetinidol and the first ‘branched’[4,6 : 4,8 : 4,6]-2,3-trans-3,4-cis : 2′,3′-trans-3′,4′-trans : 2″,3″-trans-3″,4″-trans : 2‴,3‴-trans-tetrafisetinidol.
(+)-(2 R)-2,3-反式-3,4-反式-flavan-3,3',4,4',7-戊醇[(+)-molacsacacidin]的缩合与过量的(– )-(2 R)-2,3-反式-flavan-3,3',4',7-四醇[(–)-fisetinidol]超出了预期的双黄酮范围,从而产生了两个“线性” [[ 4,6:4,6] -2,3-反-3,4-顺:2',3'-反-3',4'-反:2″,3″-反-三氟西尼多和第一个'分支的[[4,6:4,8:4,6] -2,3-反-3,4-顺:2',3'-反-3',4'-反:2″,3″-反式-3″,4″-反式:2 ‴ ,3 ‴ -反式-四氟西尼多。