One-Pot Glycosylation (OPG) for the Chemical Synthesis of Oligosaccharides

This review provides a comprehensive survey of pot (OPG) strategy for chemical synthesis of oligosacchari des, covering literatures from first example reported by Kahne and Raghavan in 1993 through May 2003. essence of OPG is to distinguish reactivity difference of a pair of glycosylation donors or acceptors so as to carry out two glycosylation steps sequentially without purification of first-step coupling product. Accordingly, literature reports are grouped based on major stereoelectronic factors causing reactivity differences, those include effect, orthogonality of leaving distinguishable acceptors, and the hybrid. The hybrid OPG procedure takes advantage of a combination of reactivity disparity of a set of armed-disarmed donors, orthogonal leaving groups, as well as acceptors so as to proceed three or more steps of glycosylation sequentially in one pot. Relevant conception and exploitation of reactivity differences of donors and acceptors in synthesis of oligosaccharides, which finally evolve OPG or advance parallelly, are briefly described at beginning.