title: Stereoselective synthesis of 2,3-diamino-2,3-dideoxy-β-D-mannopyranosyl uronates.
abstract: With the aim to find an efficient synthetic procedure for the construction of 2,3-diamino-2,3-dideoxy-β-D-mannuronic acids, we evaluated three mannosyl donors: (S)-phenyl 4,6-di-O-acetyl-2,3-diazido mannopyranoside, (S)-phenyl 2,3-diazido-4,6-O-benzylidene mannopyranoside, and (S)-phenyl 2,3-diazido mannopyranosyl methyl uronate. The first two mannosylating agents are rather unselective or slightly α-selective in their condensation with three different acceptors. The mannuronic acid donor on the other hand reliably provides the desired β-mannosidic linkage. A mechanistic rationale is put forward to account for the different behavior of the three donor types. Suitably protected 2,3-diazido mannuronic acids were employed to construct the all-cis-linked tetrasaccharide repeating unit of the capsular polysaccharide of Bacillus stearothermophilus , featuring two 2,3-diacetamido-2,3-dideoxy-β-D-mannuronic acids.
authors.affiliation: Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands.
authors.forename: Marthe T C
authors.initials: MT
authors.lastname: Walvoort
authors.forename: Gert-Jan
authors.initials: GJ
authors.lastname: Moggré
authors.forename: Gerrit
authors.initials: G
authors.lastname: Lodder
authors.forename: Herman S
authors.initials: HS
authors.lastname: Overkleeft
authors.forename: Jeroen D C
authors.initials: JD
authors.lastname: Codée
authors.forename: Gijsbert A
authors.initials: GA
authors.lastname: van der Marel
mesh_terms: D001411:Geobacillus stearothermophilus / Q000737:chemistry; D008358:Mannose / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry; D013237:Stereoisomerism; D014574:Uronic Acids / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D011134:Polysaccharides; D014574:Uronic Acids; D008358:Mannose