Anomeric reactivity-based one-pot oligosaccharide synthesis: A rapid routeto oligosaccharide libraries

The assembly of an oligosaccharide library has been achieved in a practical and efficient manner employing a one-pot sequential approach. With the hel p of the anomeric reactivity values of thioglycosides, using a thioglycosid e (mono- or disaccharide) with one free hydroxyl group as acceptor and dono r coupled with another fully protected thioglycoside, a di- or trisaccharid e is selectively formed without self-condensation and subsequently reacted in situ with an anomerically inactive glycoside (mono- or disaccharide) to form a tri- or tetrasaccharide in high overall yield. The approach enables the rapid assembly of 33 linear or branched fully protected oligosaccharide s using designed building blocks. These fully protected oligosaccharides ha ve been partially or completely deprotected to create 29 more structures to further increase the diversity of the library.