Synthesis of Quercetin 3-O-[6″-O-(trans-p-Coumaroyl)]-β-D-Glucopyranoside

This report describes the efficient synthesis of quercetin 3-O-[6″-O-(trans-p-coumaroyl)]-β-D-glucopyranoside 1 (isoquercitrin coumarate), an acylated quercetin glycoside possessing antihypertensive, antidiabetic, and tyrosinase inhibitory activities. The synthesis is initiated from commercially available quercetin via regioselective benzylation of quercetin to produce 4′, 7-di-O-benzylquercetin (4). Through 4, 1 was successfully achieved via selective β-glycosylation of the 3-OH, acylation of 6″-OH, and finally debenzylation via catalytic transfer hydrogenation.