Microwave-assisted sulfonation of heparin oligosaccharides

The use of microwaves for the efficient and fast O-sulfonation of heparin oligosaccharide intermediates has been reported for the first time. Experimental problems typically associated with this chemical reaction, such as poor isolated yields and long reaction times, have been avoided with the present method. The efficiency of this protocol was demonstrated by the high-yielding sulfonation of a series of oligosaccharides using SO3·Me3N complex. Microwave-assisted sulfonation is expected to greatly facilitate the preparation of heparin oligosaccharides, a crucial step for understanding the role of these complex carbohydrates in biological processes.