title: Tricyclic furanoid dichloroacetyl orthoesters of D-mannose from 1,2-O-trichloroethylidene-beta-D-mannofuranose.
abstract: 1,2-O-(R)-Trichloroethylidene-beta-D-mannofuranose (1) was obtained from the reaction of D-mannose with chloral. Reaction of 1 with potassium tert-butoxide (3 Mequiv) gave the thermodynamically stable 1,2,5-O-orthodichloroacetyl-beta-D-mannofuranose as the sole product whereas 1.5 Mequiv of reagent gave the kinetically controlled 1,2,3-O-orthodichloroacetyl-beta-D-mannofuranose (10) as the main product. Orthoester 10 gave the 5,6-isopropylidene derivative, which was also obtained from the reaction of 5,6-O-isopropylidene-1,2-O-(R)-trichloroethylidene-beta-D-mannofuranose with potassium tert-butoxide (1.5 Mequiv). These novel orthoesters are expected to prove useful as protecting groups and as building blocks in the formations of new mannofuranisidic units.
authors.affiliation: Ege University, Faculty of Science, Department of Chemistry, Bornova, 35100 Izmir, Turkey.
authors.forename: Yeşim
authors.initials: Y
authors.lastname: Gül Salman
authors.forename: Gökhan
authors.initials: G
authors.lastname: Kök
authors.forename: Levent
authors.initials: L
authors.lastname: Yüceer
mesh_terms: D000080:Acetals / Q000737:chemistry*; D001671:Biochemistry / Q000379:methods; D002241:Carbohydrates / Q000737:chemistry*; D002384:Catalysis; D005663:Furans / Q000737:chemistry*; D006031:Glycosylation; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008358:Mannose / Q000031:analogs & derivatives* / Q000737:chemistry*; D008956:Models, Chemical; D011522:Protons; D013816:Thermodynamics; D014241:Trichloroethylene / Q000737:chemistry
chemical_list: C496676:1,2-O-trichloroethylidenemannofuranose; D000080:Acetals; D002241:Carbohydrates; D005663:Furans; D011522:Protons; D014241:Trichloroethylene; D008358:Mannose