The focus of this research is the development of synthetic methods for oligosaccharides that rely on the use of selective protecting groups. The work couples theoretical studies with synthetic studies and applies Dr. Fraser-Reid's "armed/disarmed" methodology to the chemistry of n-pentenyl glycosides. %%% With this renewal award, the Synthetic Organic Program is supporting the research of Dr. Bert O. Fraser-Reid of the Department of Chemistry at Duke University. Professor Fraser-Reid will focus his work on the synthesis and theory of the synthesis of oligosaccharides. The oligsaccharides are compounds that can serve as mechanistic probes in the study of complex carbohydrates, natures most ubiquitous molecules.