Novel synthesis of oligosaccharides linked with carbamate and urea bonds utilizing modified Curtius rearrangement

We describe a novel synthesis of various carbamate- and urea-linked disaccharides stereospecifically using sugar carboxylic acids and sugar alcohols or sugar amines by the modified Curtius rearrangement. In this reaction, the reactivity of each hydroxyl group in glucose as an acceptor has been disclosed. Furthermore, we applied this method to the synthesis of carbamate-linked oligosaccharides including a dendritic molecule.