Synthesis of non-glycosidically linked selenoether pseudodisaccharides

Non-glycosidically linked disaccharide mimetics with a selenoether functionality linking the two monosaccharide residues have been synthesised. Protected Glc(Se3–3)Glc, Glc(Se3–6)Glc and Glc(Se3–6)Man structures were obtained. Selenium was introduced by displacement of carbohydrate sulfonates with a selenobenzoate anion. Conversion into diselenides by methanolysis of the benzoate and aerial oxidation was followed by reduction of the diselenides to selenolates, and in situ displacement of a second carbohydrate sulfonate in an SN2 reaction to give selenoethers. Glc(Se3–3)Glc and Glc(Se3–6)Glc were also obtained in deprotected form.