title: Synthesis of glycosyl(thio)ureido sugars via carbodiimides and their conformational behaviour in water.
abstract: The preparation of sugar ureas and thioureas by nucleophilic addition of water or hydrogen sulfide, respectively, to sugar-derived carbodiimides has been examined. Acetic acid efficiently catalysed the formation of ureas, whereas silica gel was found to be a more convenient catalyst in the case of the thioxo analogues. The procedures have been exploited in the development of an amine- and isocyanate-free synthesis of urea- and thiourea-tethered pseudooligosaccharides via the corresponding glycosylcarbodiimido sugars. The fully unprotected compounds adopted, preferentially, the (Z,Z) configuration at the pseudoamide bonds in water solution.
authors.affiliation: Departamento de Química Orgánica, Facultad de Química, Universidad de Sevilla, Spain.
authors.forename: V M
authors.initials: VM
authors.lastname: Díaz Pérez
authors.forename: C O
authors.initials: CO
authors.lastname: Ortiz Mellet
authors.forename: J
authors.initials: J
authors.lastname: Fuentes
authors.forename: J M
authors.initials: JM
authors.lastname: García Fernández
mesh_terms: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents / Q000737:chemistry; D002234:Carbodiimides / Q000737:chemistry*; D002236:Carbohydrate Conformation; D006027:Glycosides / Q000138:chemical synthesis / Q000737:chemistry*; D018716:Molecular Mimicry; D019906:Nuclear Magnetic Resonance, Biomolecular; D012996:Solutions; D013237:Stereoisomerism; D013890:Thiourea / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D014867:Water
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D002234:Carbodiimides; D006027:Glycosides; D012996:Solutions; D014867:Water; D013890:Thiourea