Total Synthesis of Conjugation-Ready Hyperbranched Pentasaccharide of VKM Ac-2641 by [Au]/[Ag] Catalysis.

Infections by spp. cause an economic burden to farmers. The components present in the cell wall glycopolymers (CWGs) are important for studying the host-pathogen interactions, colonization, and infection. A pentasaccharide containing a hyperbranched Rib-, Gal-, and Man- has recently been identified. Herein, we describe the first total synthesis of the conjugation-ready hyperbranched pentasaccharide of VKM Ac-2641 using the [Au]/[Ag]-catalyzed glycosidation chemistry of ethynylcyclohexyl carbonate glycosyl donors. The pentasaccharide was synthesized in a highly convergent fashion from readily accessible monosaccharide building blocks.