A novel flexible assembly strategy is described for the modular synthesis of heparin and heparansulfates. The reported strategy uses monomeric building bocks to construct the oligosaccharide chain toattain a maximum degree of flexibility. In the assembly, 1-hydroxyl glucosazido- and 1-thio uronic aciddonors are combined in a sequential glycosylation protocol using sulfonium triflate activator systems. Thekey 1-thio uronic acids were obtained in an efficient manner from diacetone glucose employing a chemo-and regioselective oxidation of partially protected glucose and idose thioglycosides.
