Sho Matsuda

Preparation of partially benzylated mono-, di-, and trisaccharides by selective cleavage of the β-fructofuranosidic linkage in fully benzylated sucrose and sucrose-related oligosaccharides under acidic conditions

Several partially benzylated mono-, di-, and trisaccharides having an anomeric hydroxyl group were successfully prepared by selective cleavage of the beta-fructofuranosidic linkage in fully benzylated sucrose and sucrose-related oligosaccharides derived from lactosucrose, raffinose, melezitose, stachyose, and nystose under acidic conditions using 1:10 75% aqueous sulfuric acid-dioxane at room temperature for 1h.

The Brfnsted Acid-catalyzed O-Glycosidation of 1-C-Alkyl-D-glucopyranose Derivatives

We found that the O-glycosidation between various kinds of 1-C-alkyl-2,3,4,6-tetra-O-benzyl-D-glucopyanoses and alcohols in the presence of 5 mol % of trifluoromethanesulfonic acid or bis(trifluoromethane)sulfonimide stereoselectively produced the corresponding 1 -C-alkyl-a-D-glucopyranosides in good yields.

Reactions and uses of artificial ketoses

- Some artificial ketoses having a naturally occurring aldose backbone can be readily prepared by the addition of RLi or RMgX to aldonolactone derivatives. They are expected to be a novel class of carbohydrate reagents for synthesizing valuable compounds. In order to utilize these ketoses completely, we must elucidate the reaction characteristics influenced by the ketoses specific structures. In particular, it is important to understand the reaction specificities of the nucleophilic substitutions at the anomeric carbons of these ketoses to produce various ketosides. This review describes the nucleophilic reactions to form the ketosidic linkages from the artificial ketoses, focusing mainly on our recent research results.

Synthesis of a Novel D-Glucose-Conjugated 15-Crown-5 Ether with a Spiro Ketal Structure

This paper describes a synthetic approach to a novel D-glucose-conjugated 15-crown-5 ether having a spiroketal structure starting from a 1-C-vinylated glucose derivative. The approach consists of the glycosylation of the vinylated glucose derivative to give an ethyleneoxy spacer derivative using bismuth(III) triflate, the conversion of the 1-C-vinyl group of the glucoside produced into a carboxylic acid group, and the intramolecular condensation between the carboxyl group and the terminal hydroxyl group in the ethyleneoxy spacer. A D-glucose-conjugated 15-crown-5 ether having a unique spiroketal structure was thus successfully synthesized.

L-fructo- and D-psicofuranosylation reactions catalyzed by scandium triflate

This paper describes the formation of L-fructo- and D-psicofuranosidic bonds by the scandium triflate catalyzed glycosidation. The reaction of the benzoylated L-fructofuranosyl acetate with an alcohol in the presence of 5 mol% scandium triflate in toluene at room temperature for 3 h stereoselectively afforded the corresponding α-L-fructofuranoside in good yields. Several α-D-psicofuranosides were predominantly obtained in good yields by the reactions between the benzoylated D-psicofuranosyl acetate and alcohols under similar reaction conditions. This method successfully provided the sucrose mimics composed of D-glucopyranose and L-fructofuranose or D-psicofuranose.

Identification of the inclusion complexation between phenyl β-d-(13C6)glucopyranoside and α-cyclodextrin using 2D 1H or 13C DOSY spectrum

This study describes the 2D 1H and 13C diffusion-ordered NMR spectroscopy (DOSY) experiments using the mixed sample of α-cyclodextrin (α-CyD) and phenyl β-d-(13C6)glucopyranoside (1). Both the 2D 1H and 13C DOSY spectra showed the component with a diffusion coefficient different from those of α-CyD and 1, which suggested the inclusion complexation of α-CyD with 1.

A synthetic approach to anhydroketopyranoses having a 6,8-dioxabicyclo〔3.2.1〕octane structure from ketopyranoses

We investigated a synthetic approach to the anhydroketopyranoses having a 6,8-dioxabicyclo[3.2.1]octane structure from D -glucopyranose derivatives. The paper describes the nucleophilic addition of the organometallic reagents RLi or RMgX to the glucono-1,5-lactone derivatives to produce the ketopyranose derivatives having a glucose backbone and their intramolecular cyclization into the desired structural anhydroketopyranoses.