Total Synthesis of the Natural Products Ulmoside A and (2R,3R)-Taxifolin-6-C-β-d-glucopyranoside
Venkateswara Rao Batchu, Lingamurthy Macha, Aravind Reddy Dorigundla, Raju Gurrapu, Umamaheswara Sarma Vanka
Abstract
An efficient first total synthesis of highly polar ulmoside A and (2R,3R)-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.