51016-10-5Relevant academic research and scientific papers
From d-glucuronic acid to l-iduronic acid derivatives via a radical tandem decarboxylation-cyclization
Salamone, Stéphane,Boisbrun, Michel,Didierjean, Claude,Chapleur, Yves
, p. 99 - 105 (2014/03/21)
A synthesis to l-iduronic derivatives, major components of heparin derived pentasaccharides was accomplished by formal inversion of configuration at C-5 of a d-glucuronic acid derivative through radical formation at C-5 using Barton decarboxylation followed by intramolecular radical addition on an acetylenic tether at O-4 giving exclusively a bicyclic sugar of l-ido configuration. Oxidation and ring opening of this bicyclic sugar led to a l-iduronate. This method opens the way to short syntheses of pentasaccharidic moiety of Idraparinux and congeners.
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.
Defining oxyanion reactivities in base-promoted glycosylations
Matwiejuk, Martin,Thiem, Joachim
supporting information; experimental part, p. 8379 - 8381 (2011/09/14)
Saccharide oxyanions obtained by base treatment could be employed in glycosylation to give oligosaccharides with high stereo- and regioselectivities.
Introduction of a chiral centre on C-6 of a carbohydrate unit: Application to the synthesis of the C-2 to C-15 fragment of ionomycin
Nicoll-Griffith,Weiler
, p. 2733 - 2750 (2007/10/02)
Glucose is converted into the α,β-unsaturated urono-8,4-lactone 29 using an intramolecular Wadsworth-Emmons reaction. Higher order cuprates add to the lactone to provide the C-6 substituted carbohydrate derivative with high stereoselectivity. This product can be converted into the dithiane 34b which when coupled with an appropriate epoxide yields compound 37 which contains the C-2 to C-15 fragment of ionomycin with the correct absolute stereochemistry at each asymmetric centre for conversion into ionomycin.
Preparation of Some Partially Methylated Galactosides from Methyl α-D-Galactopyranoside
Roy, Abhijit,Batavyal, Lakshmi,Roy, Nirmolendu
, p. 498 - 499 (2007/10/02)
Methyl 2,3,6-tri-O-methyl-α-D-galactopyranoside (3) and methyl 2,6-di-O-methyl-α-D-galactopyranoside (2) have been synthesized starting from isopropylidene derivatives of methyl α-D-galactopyranoside.
SYNTHESIS OF METHYL DERIVATIVES OF URONIC ACIDS. II. SYNTHESIS OF THE 2,3-, 2,4-, AND 2,4-DI- AND 2,3,4-TRI-O-MEETHYL ETHERS OF METHYL (METHYL α-D-GALACTOPYRANOSID)URONATE
Grishkovets, V. I.,Zemlyakov, A. E.,Chirva, V. Ya.
, p. 259 - 261 (2007/10/02)
Unidirectional methods are proposed for the synthesis of the 2,3-, 2,4-, and 3,4-di-, and 2,3,4-tri-O-methyl ethers of methyl (methyl α-D-galactopyranosid)uronate by the oxidation (CrO3-H2SO4-acetone) of the corresponding methyl O-benzyl-O-methyl-α-D-galactopyranosides having unsubstituted 6-OH groups to the corresponding (methyl O-benzyl-O-methyl-α-D-galactosid)uronic acids followed by the esterification with CH2N2 and catalytic hydrogenolysis of the benzyl groups.
