Synthesis of a β-glucan polysaccharide analogue by an iterative copper-catalyzed azide-acetylene coupling reaction

A triazole-linked β-glucan analogue was prepared using a copper-catalyzed azide-acetylene coupling reaction. The alkynylsilyl moiety was inactive under the conditions of the copper-catalyzed azide-acetylene coupling reaction and was readily converted into a terminal acetylene group by treatment with tetrabutylammonium fluoride. Using the method, we successfully synthesized a β-glucan analogue containing three laminaripentaose units.