Total Synthesis of the Natural Products Ulmoside A and (2 R,3 R)-Taxifolin-6- C -β- d -glucopyranoside

Abstract

An efficient first total synthesis of highly polar ulmoside A and (2 R,3 R)-taxifolin-6- C -β- d -glucopyranoside, useful for the prevention of metabolic disorders, has been described. Key elements of the synthesis include a Sc(OTf) 3-catalyzed regio- and stereoselective C -glycosidation on taxifolin in 35% yield with d -glucose and chiral semipreparative reverse-phase high-performance liquid chromatography (HPLC) for the separation of both taxifolins and the diastereomeric mixture of taxifolin-6- C -β- d -glucopyranosides. Correlation of the analytical data of synthetic ulmoside A and its diastereomer with a natural ulmoside A sample confirmed the assigned absolute stereochemistry of the natural products.