Unified Strategy for the Concise Total Syntheses of All Six 3″-O-Acyl Quercitrins Based on Regioselective Acylation Catalyzed by Boronic Acid

Abstract

The naturally occurring 3″-O-acylquercitrin family exhibits a range of biological activities with significant potential health and medical benefits. Herein, we present a unified strategy for concise total syntheses of all six known 3″-O-acylquercitrin natural products─namely, 3″-O-galloylquercitrin, 3″-O-(E)-cinnamoylquercitrin, 3″-O-(E)-coumaroylquercitrin, 3″-O-(E)-feruloylquercitrin, 3″-O-acetylquercitrin, and 3″-O-tigloylquercitrin─based on regioselective acylation of carbohydrates catalyzed by N-methylimidazole-containing boronic acid. The core advancement in this approach is a late-stage catalytic regioselective functionalization of a common synthetic intermediate, enabling efficient access to the natural products.