13035-60-4Relevant academic research and scientific papers
Hydroxy group acidities of partially protected glycopyranosides
Matwiejuk, Martin,Thiem, Joachim
scheme or table, p. 2180 - 2187 (2012/06/30)
A comprehensive acidity study of carbohydrate hydroxy groups has been carried out. Relative acidities (Ke) were determined spectrophotometrically for partially methylated methyl α-D- glycopyranosides. Apparently, the acidity is strongly affected by intramolecular hydrogen bonding as well as stereochemistry and solvation. By comparison with pKe and pKa values of aliphatic alcohols and polyols the first estimation of the pKa values for partially protected glycopyranosides was obtained. These findings contribute to the understanding of the relative reactivities of carbohydrate hydroxy groups.
Palladium-catalyzed intramolecular C-O bond formation: An approach to the synthesis of chiral benzodioxocines
Neogi, Arpita,Majhi, Tirtha P.,Achari, Basudeb,Chattopadhyay, Partha
, p. 330 - 336 (2008/09/18)
Palladium-catalyzed intramolecular aryl etherification using bulky binaphthylphosphane or bis(diphenylphosphanyl)ferrocene ligands is shown to be a convenient method for the synthesis of eight-membered oxygen heterocycles. Application of this methodology to a sugar derivative led to the synthesis of chiral benzodioxocine. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
Sulfuric acid immobilized on silica: an efficient promoter for one-pot acetalation-acetylation of sugar derivatives
Mukhopadhyay, Balaram
, p. 4337 - 4341 (2007/10/03)
Sulfuric acid immobilized on silica gel has been used as an efficient and safe alternative promoter for acetalation and subsequent acetylation of sugar glycosides using stoichiometric reagents without work-up. The synthesis of different types of per-O-ace
Triterpenoid saponins from Becium grandiflorum var. obovatum
Burger, Irmgard,Burger, Barend V.,Albrecht, Carl F.,Spies, Hendrik S. C.,Sandor, Peter
, p. 2087 - 2095 (2007/10/03)
Two new triterpenoid saponins, beciumecine 1 and 2, were isolated from the root bark of Becium grandiflorum var. obovatum and their structures established as 3-O-(β-D-glucopyranosyl) terminolic acid 28-O-β-D- apiofuranosyl(1-3)-[α-L-rhamnopyranosyl(1-3)-β-D-xylopyranosyl(1-4)]-α-L- rhamnopyranosyl(1-2)-α-L-arabinopyranoside and 3-O-(β-D-glucopyranosyl) 24- hydroxyterminolic acid 28-O-α-L-rhamnopyranosyl(1-3)-β-D-xylopyranosyl(1- 4)-α-L-rhamnopyranosyl(1-2)-α-L-arabinopyranoside, respectively.
Chemistry of oxo-sugars. (2). Regio- and stereo-selective synthesis of methyl D-hexopyranosiduloses and identification of their forms existing in solutions
Liu,Sato,Tsuda
, p. 491 - 501 (2007/10/02)
Sixteen oxo derivatives of methyl D-hexopyranosides with various regio-and stereo-chemistries were selectively synthesized by direct oxidation of non-protected methyl glycosides by the bistributyltin oxide-bromine method or by oxidation of partially protected glycosides followed by deprotection. The forms of these oxoglycosides existing in pyridine-d5 and in H2O (D2O) were investigated by means of 13C-NMR spectroscopy, and it was found that interconversion between oxo and hydrate forms of oxoglycosides readily takes place.
New Convenient Synthesis of Tunicamine
Ramza, Jan,Zamojski, Aleksander
, p. 6123 - 6134 (2007/10/02)
A synthesis of tunicamine, the eleven-carbon atom sugar component of tunicamycin antibiotics, was described.The synthesis started from a derivative of 2-azido-2-deoxy-D-galactose (11) which was condensed with a furfuryl alcohol moiety.Achmatowicz-type tra
Studies on carbohydrates X. A new method for the preparation of isopropylidene saccharides
He,Li,Li,Liu,Qiu,Cai
, p. 2653 - 2658 (2007/10/02)
Cabohydrates reacting with acetone in the presence of molecular sieve and p-toluene sulfonic acid provided a simple, convenient, high yield and good selective process for preparation of isopropylidene carbohydrates.
Alkyloxytris(dimethylamino)phosphonium Salts. Part 21. Anomeric Hydroxy-group Activation of 2,3:4,6-Di-O-isopropylidene-α-D-mannopyranose, Thioglycosylation and Glycosylation
Chretien, Francoise,Chapleur, Yves,Castro, Bertrand,Gross, Bernard
, p. 381 - 384 (2007/10/02)
The action of carbon tetrachloride and tris(dimethylamino)phosphine at low temperature on 2,3:4,6-di-O-isopropylidene-α-D-mannopyranose affords the α anomeric form of the corresponding alkoxytris(dimethylamino)phosphonium chloride.The condensation of arom
