ABSTRACT

An example of this strategy consists of a two-stage activation method as reported by Nicolaou [2]. Thus, a glycosyl fluoride derived from the corresponding phenylthioglycoside by simple treatment with NBS-DAST, is allowed to couple with a phenylthioglycoside to give a disaccharide. Conversion into the disaccharide fluoride as described in the foregoing allows an iterative process to be considered. Similarly, Danishefsky [3] reported an iterative strategy for the stereocontrolled construction of 13-linked 1,6-glycal acceptors and repetition of the process. The method has been explored for applications to solid-phase synthesis of 1,6-linked oligosaccharides [4].