title: Toward the automated solid-phase synthesis of oligoglucosamines: systematic evaluation of glycosyl phosphate and glycosyl trichloroacetimidate building blocks.
abstract: Glucosamines are common components of many biologically important oligosaccharides. Reported is a systematic evaluation of glucosamine phosphates and trichloroacetimidates as glycosylating agents for the efficient construction of beta-(1 --> 6) glucosamine linkages. A set of differentially protected glucosamine donors incorporating a host of amine protecting groups, including 2-phthaloyl, benzyloxycarbonyl (Z), trichloroetheoxycarbonyl (Troc) and trichloroacetyl (TCA) protective groups, were prepared. Donors were initially evaluated for reactivity and protecting group compatibility in a solution-phase study with a model 6-hydroxyl galactose acceptor. Based on these results, glucosamine donor 10 was selected for the solution-phase synthesis of a beta-(1 --> 6)-glucosamine pentasaccharide. Finally, building block 10 proved well suited for use in the automated solid-phase synthesis of a repeating unit trisaccharide. An assessment of glucosamine phosphate donors as potential glycosylating agents for a variety of glucosamine linkages is also discussed.
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Luis G
authors.initials: LG
authors.lastname: Melean
authors.forename: Kerry R
authors.initials: KR
authors.lastname: Love
authors.forename: Peter H
authors.initials: PH
authors.lastname: Seeberger
mesh_terms: D000081:Acetamides; D001331:Automation; D062845:Chloroacetates; D020650:Combinatorial Chemistry Techniques; D005944:Glucosamine / Q000138:chemical synthesis*; D006027:Glycosides / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D009844:Oligosaccharides / Q000138:chemical synthesis*; D013403:Sugar Phosphates / Q000737:chemistry; D014238:Trichloroacetic Acid / Q000737:chemistry
chemical_list: D000081:Acetamides; D062845:Chloroacetates; D006027:Glycosides; D009844:Oligosaccharides; D013403:Sugar Phosphates; D014238:Trichloroacetic Acid; C009528:trichloroacetamide; D005944:Glucosamine