General synthesis of epi-series catechins and their 3-gallates: reverse polarity strategy
作者:Ken Ohmori、Takahisa Yano、Keisuke Suzuki
DOI:10.1039/c003464a
日期:——
A general synthetic route to the epi-series catechins was developed based on the reverse polarity strategy. Aromatic nucleophilic substitution reaction followed by the sulfinyl–metal exchange and cyclization enabled stereo-controlled access to various members of epi-series catechins and their 3-gallates.
The present invention provides a method for producing flavan derivatives having various substituent groups with controlling the stereochemistry. The method of the present invention includes the steps of: hydratively condensing a phenol compound expressed by formula (I) and an alcohol compound expressed by formula (II) to from an epoxide compound of formula (III); opening the epoxy ring of the epoxide compound of formula (III) to form an iodine-containing compound of formula (IV); and cyclizing the iodine-containing compound to form the flavan derivative of formula (V).
US7820835B2
申请人:——
公开号:US7820835B2
公开(公告)日:2010-10-26
Stereocontolled Synthesis of (−)-Afzelechin: General Route to Catechin-class Polyphenols by Solving an S<sub>N</sub>2 vs. S<sub>N</sub>1 Problem
Stereocontrolled synthesis of (−)-afzelechin was achieved via the Mitsunobu reaction, where complete stereospecificity was observed when an electron-withdrawing group was introduced to the para-position of the B-ring fragment.
通过 Mitsunobu 反应实现了 (-)-afzelechin 的立体定向合成,当在 B 环片段的对位引入一个抽电子基团时,可观察到完全的立体特异性。