3,4-anhydro-1,2-O-isopropylidene-beta-D-tagatopyranose and 4,5-Anhydro-1,2-O-isopropylidene-beta-D-fructopyranose
Autor: | Maria Lyssikatou, Alan R. Edgar, Mary F. Mahon, Pauline M. Welsh, Masoud Ataie, R.G. Kinsman, J. Grant Buchanan |
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Rok vydání: | 2000 |
Předmět: |
Models
Molecular Magnetic Resonance Spectroscopy Organic Chemistry Epoxide General Medicine Fructose Carbon-13 NMR Ring (chemistry) Crystallography X-Ray Biochemistry Medicinal chemistry Sodium methoxide Carbon Analytical Chemistry Acetic acid chemistry.chemical_compound Stereospecificity chemistry Aqueous sodium hydroxide Epoxy Compounds Glycosides Spectroscopy Hydrogen |
Zdroj: | Carbohydrate research. 323(1-4) |
ISSN: | 0008-6215 |
Popis: | 3,4-Anhydro-1,2- O -isopropylidene-β- d -tagatopyranose ( 8 ) and 4,5-anhydro-1,2- O -isopropylidene-β- d -fructopyranose ( 10 ) have been prepared by treatment of 3,5-di- O -acetyl-1,2- O -isopropylidene-4- O -toluene- p -sulfonyl-β- d -fructopyranose with methanolic sodium methoxide. The structures of 8 and 10 were assigned by 1 H and 13 C NMR spectroscopy and that of 10 by X-ray crystallography; both exist in half-chair conformations. Compounds 8 and 10 interconvert in aqueous sodium hydroxide, giving a ratio of 1:2 at equilibrium. The monoacetates of 8 and 10 (5- O -acetyl-3,4-anhydro-1,2- O -isopropylidene-β- d -tagaopyranose and 3- O -acetyl-4,5-anhydro-1,2- O -isopropylidene-β- d -fructopyranose) undergo stereospecific epoxide ring opening in 80% acetic acid to give mainly the axial monoacetates 5- O -acetyl-1,2- O -isopropylidene-β- d -fructopyranose and 4- O -acetyl-1,2- O -isopropylidene-β- d -tagatopyranose, respectively. |
Databáze: | OpenAIRE |
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