title: Convergent stereoselective synthesis of multiple sulfated GlcNα(1,4)GlcAβ(1,4) dodecasaccharides.
abstract: In this paper, we describe an effective method for the elongation of a GlcNα(1,4)GlcAβ(1,4) sequence using a GlcNTrocα(1,4)GlcA disaccharide unit and the synthesis of the N- and/or O-sulfated GlcNα(1,4)GlcAβ(1,4) oligosaccharides. N-Troc protection of GlcNα(1,4)GlcA units was effective for the synthesis of the GlcNα(1,4)GlcAβ(1,4) oligosaccharides in comparison with the azido substituent. The GlcNα(1,4)GlcAβ(1,4) dodecasaccharide was successfully prepared by the direct β-selective glycosidation of glucuronate in the GlcNα(1,4)GlcAβ(1,4)GlcNα(1,4)GlcAβ(1,4) tetrasaccharide. In addition, the synthesis of the N- and/or O-sulfated GlcNα(1,4)GlcAβ(1,4) oligosaccharides was accomplished by fluorous-assisted deprotection and sulfation. The fluorous-assisted synthetic technology applied to the highly polar sulfated oligosaccharide permits it to be more easily separated from the highly polar reagents, such as SO(3)·NEt(3).
authors.affiliation: Department of Applied Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1-H-101 Ookayama, Meguro, Tokyo 152-8552, Japan. thiroshi@apc.titech.ac.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tanaka
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Tateno
authors.forename: Takashi
authors.initials: T
authors.lastname: Takahashi
mesh_terms: D002236:Carbohydrate Conformation; D060326:Chemistry Techniques, Synthetic / Q000379:methods*; D004187:Disaccharides / Q000737:chemistry*; D005944:Glucosamine / Q000737:chemistry*; D020723:Glucuronic Acid / Q000737:chemistry*; D009844:Oligosaccharides / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D013457:Sulfur Compounds / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D004187:Disaccharides; D009844:Oligosaccharides; D013457:Sulfur Compounds; C560363:heparosan; D020723:Glucuronic Acid; D005944:Glucosamine