ChemInform Abstract: 3,4-Anhydro-1,2-O-isopropylidene-β-D-tagatopyranose and 4,5-Anhydro-1,2-O-isopropylidene-β-D-fructopyranose

Autor: Mary F. Mahon, Pauline M. Welsh, Maria Lyssikatou, Alan R. Edgar, Masoud Ataie, J. Grant Buchanan, R.G. Kinsman
Rok vydání: 2010
Předmět:
Zdroj: ChemInform. 31
ISSN: 1522-2667
0931-7597
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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