title: Multigram-scale synthesis of an orthogonally protected 2-acetamido-4-amino-2,4,6-trideoxy-D-galactose (AAT) building block.
abstract: Reported is the gram-scale synthesis of tert-butyldiphenylsilyl 4-(N-benzyloxycarbonyl)-amino-2-azido-2,4,6-trideoxy-β-D-galactopyranoside, which represents an orthogonally protected 2,4-diamino-D-fucose building block, a common constituent of various zwitterionic polysaccharides. The building block has been synthesized from D-glucosamine in 19% overall yield over 14 steps, requiring 5 chromatographic purifications. The key step in the synthesis is the introduction of the C-4 amino substituent, which has been accomplished by a one-pot three step procedure, involving regioselective C-3-O-trichloroacetimidate formation, C-4-O-triflation, and intramolecular substitution. The building block can be used as an acceptor and is readily transformed into a donor glycoside.
authors.affiliation: Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands.
authors.forename: A E
authors.initials: AE
authors.lastname: Christina
authors.forename: V M
authors.initials: VM
authors.lastname: Blas Ferrando
authors.forename: F
authors.initials: F
authors.lastname: de Bordes
authors.forename: W A
authors.initials: WA
authors.lastname: Spruit
authors.forename: H S
authors.initials: HS
authors.lastname: Overkleeft
authors.forename: J D C
authors.initials: JD
authors.lastname: Codée
authors.forename: G A
authors.initials: GA
authors.lastname: van der Marel
mesh_terms: D000081:Acetamides; D001386:Azides / Q000737:chemistry*; D062845:Chloroacetates; D002855:Chromatography, Thin Layer; D005643:Fucose / Q000031:analogs & derivatives* / Q000737:chemistry; D005690:Galactose / Q000031:analogs & derivatives* / Q000737:chemistry; D005944:Glucosamine / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008698:Mesylates / Q000737:chemistry; D015394:Molecular Structure; D017646:Organosilicon Compounds / Q000737:chemistry*; D013237:Stereoisomerism; D014238:Trichloroacetic Acid / Q000737:chemistry
chemical_list: C550267:2-acetamido-4-amino-2,4,6-trideoxy-D-galactose; D000081:Acetamides; D001386:Azides; D062845:Chloroacetates; D008698:Mesylates; D017646:Organosilicon Compounds; D005643:Fucose; D014238:Trichloroacetic Acid; C009528:trichloroacetamide; C012077:trifluoromethanesulfonic acid; D005944:Glucosamine; D005690:Galactose