title: Carbohydrate-derived spiroketals. Stereoselective synthesis of di-D-fructose dianhydrides by boron trifluoride promoted glycosylation-spiroketalization of acetal precursors.
abstract: [reaction: see text] Di-D-fructose 1,2':2,1'-dianhydrides, dispiro-tricyclic disaccharides widely found in food materials, have been stereoselectively prepared in one-pot reaction from O-protected D-fructose 1,2-acetonide precursors by treatment with boron trifluoride diethyl etherate. The dimerization sequence involves (i) cleavage of the anomeric acetal linkage, (ii) autoglycosylation, and (iii) final spiroketalization, the stereochemical outcome being strongly dependent on the nature of the hydroxyl protecting groups.
authors.affiliation: Departamento de Química Orgánica, Facultad de Química, Universidad de Sevilla, Aptdo. 553, E-41071 Sevilla, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Benito
authors.forename: M
authors.initials: M
authors.lastname: Gómez-García
authors.forename: C
authors.initials: C
authors.lastname: Ortiz Mellet
authors.forename: J M
authors.initials: JM
authors.lastname: García Fernández
authors.forename: J
authors.initials: J
authors.lastname: Defaye
mesh_terms: D001880:Boranes / Q000737:chemistry; D004187:Disaccharides / Q000138:chemical synthesis* / Q000737:chemistry; D005632:Fructose / Q000031:analogs & derivatives / Q000138:chemical synthesis* / Q000737:chemistry; D006031:Glycosylation; D008968:Molecular Conformation; D013141:Spiro Compounds / Q000737:chemistry; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
chemical_list: D001880:Boranes; D004187:Disaccharides; D013141:Spiro Compounds; D005632:Fructose; C021274:boron trifluoride