A chemical glycosylation reaction involves the coupling of a glycosyl donor, to a glycosyl acceptor forming  a glycoside. If both the donor and acceptor are sugars, then the product is an  oligosaccharide.  The reaction requires activation with a suitable activating reagent.  The reactions often result in a mixture of products due to the creation of a new stereogenic centre at the anomeric position of the glycosyl donor.  The formation of a glycosidic linkage allows for the synthesis of complex polysaccharides which may play important roles in biological processes and pathogenesis and therefore having synthetic analogs of these molecules allows for further studies with respect to their biological importance.