Condensed Tannins: The Formation of a Diarylpropanol-Catechinic Acid Dimer from Base-Catalyzed Reactions of (+)-Catechin
作者:
Seiji Ohara,
RichardW. Hemingway,
期刊:
Journal of Wood Chemistry and Technology
(Taylor Available online 1991)
卷期:
Volume 11,
issue 2
页码: 195-208
ISSN:0277-3813
年代: 1991
DOI:10.1080/02773819108050270
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
Reaction of (+)-catechin at pH 12 and 40 °c results in the stereoselective (if not stereospecific) formation of an enolic form of 1-[6-(3′,4′-dihydroxyphenyl)-7-hydroxybicyclo[3.3.1]nonane-2,4,9-trione-3-yl] -1-(3,4-dihyroxyphenyl)-3-(2,-4,6-trihydroxyphenyl)-propan-2-ol. The n.m.r. chemical shift assignments determined by a variety of two-dimensional experiments permit a conclusion that the compound is one of four diastereoisomers possible from reaction of the two quinone methide intermediates. Stereoselectivity in the formation of this compound can be accounted for by preference forRe-face attack on both 2-C's of the quinone methides involved in the formation of the molecule.
点击下载:
PDF (489KB)
返 回