Total Synthesis and Preliminary Biological Evaluation of the Natural Glycolipids Cupacinoside and Dalberoside

We report the total synthesis of the glycolipid natural products cupacinoside (1) and dalberoside (2), together with an alkynemodified analogue (3). The synthesis features two α-selective rhamnosylations and a β-selective glucosidation as key steps. Analague 3 was further derivatized to afford a BODIPY-labeled fluorescent glycolipid probe for functional and mechanistic studies. Prelinimary antimicrobial assays are reproted. We anticipate this work will facilitate synthesis and biological investigation of other glycolipid natural products and related chemical probes.