title: Easy and stereoselective approach to alpha,beta-unsaturated gamma-lactones fused to pyranoses from furanose scaffolds.
abstract: The first facile and efficient route to pyranose-fused butenolides from furanose scaffolds, convenient for scaling up production, is described. Wittig olefination of 1,2-O-isopropylidene pentofuranos- or hexofuranos-3-uloses with a resonance-stabilized ylide led to the stereoselective formation of the (Z)-alpha,beta-unsaturated ester. In the presence of acid labile 5-O- or 5,6-di-O-protecting groups, acid hydrolysis of the Wittig product resulted in isomerization to the pyranose form and spontaneous lactonization to give the target molecules in good overall yield.
authors.affiliation: Departamento de Química e Bioquímica/Centro de Química e Bioquímica da Faculdade de Ciências da Universidade de Lisboa, Ed. C8, 5o Piso, 1749-016 Lisboa, Portugal.
authors.forename: Nuno M
authors.initials: NM
authors.lastname: Xavier
authors.forename: Amélia P
authors.initials: AP
authors.lastname: Rauter
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D001067:Appetite Depressants; D005663:Furans / Q000737:chemistry; D006601:Hexoses / Q000737:chemistry; D007166:Immunosuppressive Agents; D007783:Lactones / Q000737:chemistry*; D011714:Pyrans / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D001067:Appetite Depressants; D005663:Furans; D006601:Hexoses; D007166:Immunosuppressive Agents; D007783:Lactones; D011714:Pyrans; C004511:butenolide; D015107:4-Butyrolactone