作者:Kazuma Shioe、Yusuke Sahara、Yoshikazu Horino、Takashi Harayama、Yasuo Takeuchi、Hitoshi Abe
DOI:10.1016/j.tet.2011.01.004
日期:2011.3
Ellagitannins possess a wide range of biological activities and remarkable structural diversity, which commonly include an axially chiral biaryl unit. This paper describes syntheses of all-methylated versions of isorugosin B and rugosin B, which are regioisomeric, ellagitannin-related compounds. The key features of these syntheses involve the construction of an axially chiral biaryl function on a sugar moiety through a Pd-catalyzed intramolecular biaryl coupling reaction, Bringmann's atroposelective lactone opening reaction, and a two-step ester formation. This is the first synthetic approach for generating ellagitannins featuring a valoneoyl group. (C) 2011 Elsevier Ltd. All rights reserved.