3149-62-0

Upstream product

• 77-78-1 dimethyl sulfate 
• 617-04-9 (2R,3S,4S,5S,6S)-2-(hydroxymethyl)-6-methoxytetrahydro-2H-pyran-3,4,5-triol 
• 74-88-4 methyl iodide 
• 186581-53-3 diazomethane 
• 108-24-7 acetic anhydride 
• 3445-71-4 methyl-(tetra-O-methyl-β-D-mannopyranoside) 
• 530-26-7 D-Mannose 
• 67-56-1 methanol 
• 95690-50-9 7-Hydroxy-5-methoxy-2-[4-((2S,3R,4R,5R,6R)-3,4,5-trimethoxy-6-methoxymethyl-tetrahydro-pyran-2-yloxy)-phenyl]-chromen-4-one 
• 95690-54-3 5-Methoxy-7-((2S,3R,4R,5R,6R)-3,4,5-trimethoxy-6-methoxymethyl-tetrahydro-pyran-2-yloxy)-2-[4-((2S,3R,4R,5R,6R)-3,4,5-trimethoxy-6-methoxymethyl-tetrahydro-pyran-2-yloxy)-phenyl]-chromen-4-one 
• 95690-55-4 Acetic acid (2R,3R,4R,5R,6S)-3,4,5-trimethoxy-6-{5-methoxy-4-oxo-2-[4-((2S,3R,4R,5R,6R)-3,4,5-trimethoxy-6-methoxymethyl-tetrahydro-pyran-2-yloxy)-phenyl]-4H-chromen-7-yloxy}-tetrahydro-pyran-2-ylmethyl ester 
• 197631-81-5 phenyl 2,3,4,6-tetra-O-methyl-1-deoxy-1-thio-α-D-mannopyranoside S-oxide 

Downstream Products

• 492-93-3 1,5-anhydro-D-mannitol 

Relevant academic research and scientific papers

Calorimetric measurement of the CH/π interaction involved in the molecular recognition of saccharides by aromatic compounds

(Chemical Equation Presented) Can a benzene molecule differentiate between two isomeric carbohydrates? It is generally accepted that two factors govern molecular recognition: complementarity and preorganization. Preorganization requires the presence of cavities for positioning the host's groups of complementary nature to those of the guest. This study shows that, in fact, groups should be complementary to recognize each other (for the case presented here, it is controlled by the CH/π interaction) but preorganization is not essential. Since weak interactions have their origin in dispersion forces, they also have impact on the enthalpic term of the free energy, so it was considered that their participation can be demonstrated by measuring the energy involved. For recognition to happen, two conditions must be satisfied: specificity and associated stabilizing energy. In this study we evaluated the heat of dissolution of different carbohydrates such as methyl 2,3,4,6-tetra-O-methyl- α-D-mannopyranoside and methyl 2,3,4,6-tetra-O-methyl-β-D- galactopyranoside using different aromatic solvents. The solvation enthalpies in benzene were -78.8 ± 3.9 and -88.7 ± 5.5 kJ mol-1 for each carbohydrate, respectively; and these values yielded a CH/π energy of interaction of 9.9 kJ mol-1. In addition, NMR studies of the effect of the addition of benzene to chloroform solutions of the two carbohydrates showed that benzene specifically interacts with the hydrogen atoms of the pyranose ring at positions 3, 4, and 5 located on the α face of the methyl-β-galactoside, so it is, in fact, able to recognize it. Thus, the interactions between carbohydrates and the aromatic residues of proteins occur in the absence of the confinement generated by the protein structure. By experimentally measuring the energy associated with this interaction and comparing it to theoretical calculations, it was also possible to unequivocally determine the existence of CH/π interactions between carbohydrates and proteins.

Anomerization and transglycosylation reactions of permethylated methyl D-glycopyranosides

The anomerization reactions of permethylated methyl D-glycopyranosides in the presence of various Lewis acid catalysts, such as Me3SiOTf, Me3SiOMs, BF3 · OEt2, or TiCl4 were examined in dichloromethane solution. β Anomers of the glycosides anomerized to the α anomer very rapidly, but the anomerizations in the opposite direction were slower. Transglycosylation reactions of the glycosides in the presence of similar catalysts and ethanol gave preferably the α anomers with most substrates employed. No anomerization was observed in the case of the α-mannoside, probably because the α anomer is strongly favored at equilibrium. Nevertheless, transglycosylation took place. The anomerization reactions of permethylated methyl D-glycopyranosides in the presence of various Lewis acid catalysts, such as Me3SiOTf, Me3SiOMs, BF3·OEt2, or TiCl4 were examined in dichloromethane solution. β Anomers of the glycosides anomerized to the α anomer very rapidly, but the anomerization in the opposite direction were slower. Transglycosylation reactions of the glycosides in the presence of similar catalysts and ethanol gave preferably the α anomers with most substrates employed. No amerization was observed in the case of the α-mannoside, probably because the α anomer is strongly favored at equilibrium. Nevertheless, transglycosylation took place.

Enthalpic nature of the CH/π interaction involved in the recognition of carbohydrates by aromatic compounds, confirmed by a novel interplay of NMR, calorimetry, and theoretical calculations

Specific interactions between molecules, including those produced by a given solute, and the surrounding solvent are essential to drive molecular recognition processes. A simple molecule such as benzene is capable of recognizing and differentiating among very similar entities, such as methyl 2,3,4,6-tetra-O-methyl-α-D-galactopyranoside (α-Me5Gal), methyl 2,3,4,6-tetra-O-methyl-β-D-galactopyranoside (β-Me 5Gal), 1,2,3,4,6-penta-O-acetyl-β-D-galactopyranose (β-Ac5Gal), and methyl 2,3,4,6-tetra-O-methyl-α-D- mannopyranoside (α-Me5Man). In order to determine if these complexes are formed, the interaction energy between benzene and the different carbohydrates was determined, using Calvet microcalorimetry, as the enthalpy of solvation. These enthalpy values were -89.0 ± 2.0, -88.7 ± 5.5, -132.5 ± 6.2, and -78.8 ± 3.9 kJ mol-1 for the four complexes, respectively. Characterization of the different complexes was completed by establishing the molecular region where the interaction takes place using NMR. It was determined that β-Me5Gal is stabilized by the CH/π interaction produced by the nonpolar region of the carbohydrate on the α face. In contrast, α-Me5Man is not specifically solvated by benzene and does not present any stacking interaction. Although α-Me5Gal has a geometry similar to that of its epimer, the obtained NMR data seem to indicate that the axial methoxy group at the anomeric position increases the distance of the benzene molecules from the pyranose ring. Substitution of the methoxy groups by acetate moieties, as in β-Ac 5Gal, precludes the approach of benzene to produce the CH/π interaction. In fact, the elevated stabilization energy of β-Ac 5Gal is probably due to the interaction between benzene and the methyl groups of the acetyls. Therefore, methoxy and acetyl substituents have different effects on the protons of the pyranose ring.

Highly regioselective and stereoselective synthesis of C-Aryl glycosidesvianickel-catalyzedortho-C-H glycosylation of 8-aminoquinoline benzamides

C-Aryl glycosides are of high value as drug candidates. Here a novel and cost-effective nickel catalyzedortho-CAr-H glycosylation reaction with high regioselectivity and excellent α-selectivity is described. This method shows great functional group compatibility with various glycosides, showing its synthetic potential. Mechanistic studies indicate that C-H activation could be the rate-determining step.

New method for regioselective glycosylation employing saccharide oxyanions

As an alternative concept for glycosylation, the prior activation of acceptor hydroxy groups for selective glycosidic bond formation, was investigated to give complex oligosaccharides. Oxyanions obtained from partially protected saccharides were glycosylated by employing glycopyranosyl halides, and the regiochemical results were studied. Initially, partially methylated methyl-α-D-glucopyranosides were used as a model system to study the underlying mechanistic principles of base-promoted glycosylation. High regioselectivities and stereospecific glycosidic bond formations were achieved, and the scope of the methodology was extended with different perbenzylated glycosyl donors.

TOLL-LIKE RECEPTOR 9 AGONISTS

The present invention provides TLR9 agonists comprising, as an active ingredient, a compound represented by formula (I): (wherein a represents 0 or 1; n represents an integer of 0 to 2; m represents an integer of 0 to 5; X1 and X2 each independently represent a hydrogen atom or hydroxy; Y represents an oxygen atom or a sulfur atom; -Q1-represents -O- or the like; -Q2- represents -O- or the like; -Z- represents -O- or the like; R1, R3 and R4 each independently represent hydroxy or the like; R2 and R5 each independently represent a hydrogen atom, hydroxy or the like; and A represents 6-aminopurin-9-yl or the like) or a pharmaceutically acceptable salt thereof, and the like.

Are glycosyl triflates intermediates in the sulfoxide glycosylation method? A chemical and 1H, 13C, and 19F NMR spectroscopic investigation

The title question is addressed by low-temperature 1H, 13C, and 19F NMR spectroscopies in CD2CL2 as well as by the preparation of authentic samples from glycopyranosyl bromides and AgOTf. At -78°C glycosyl triflates are cleanly generated with either nonparticipating or particpating protecting groups at O-2. The glycosyl triflates identified in this manner were allowed to react with methanol, resulting in the formation of methyl glycosides. Glycosyl triflates were generated at -78°C in CD2Cl2 and allowed to warm gradually until decomposition was detected by 1H and 19F NMR spectroscopy. The decomposition temperature and products are functions of the protecting groups employed.

Peralkylation of Saccharides under Aqueous Conditions

Treatment of saccharides with sodium hydroxide and alkyl halides in aqueous dimethyl sulfoxide solution offers a very efficient method for the complete alkylation of saccharides in high yields.

1:1 Adduct Ion Formation of Permethylated Monosaccharides with Organic Cations in FAB Mass Spectrometry

The 1:1 adduct ion formation between a series of permethylated monosaccharides (M; Ia-Ih) and an organic or a metallic cation (A+) has been examined in quantitative FAB mass spectrometry.In a careful camparison under the same FABMS conditions, the relative (M+A)+ peak intensities increase in the following order of the monosaccharides, and further increase at nearly the same extents in spite of using three different cations such as octylammonium, (methoxycarbonyl)methylammonium, and potassium ions: β-Glc α-Glc α-Gal β-Gal /= α-Man β-Man α-Tal β-Tal.The order and cation-independency clearly indicate the OCH3 configurational effects of M on (M+A)+ adduct ion formation.The findings can be interpreted in terms of multisite electrostatic interaction of oxygens with the cation.Coupled with the results of gas-phase behavior by FABMS/MS(CAD), solution behavior by 1H NMR, and model calculations by MNDO, the characteristic structure of the 1:1 adduct ion is deduced as host-guest type association between permethylated monosaccharides and cationic species in particular cases, at least β-Tal and α-Tal cases.

METHYLATION OF METHYL α-D-HEXOPYRANOSIDES WITH DIAZOMETHANE IN THE PRESENCE OF A SMALL AMOUNT OF WATER

The long-time reaction of methyl α-D-gluco-, α-D-manno-, and α-D-galactopyranosides with excess diazomethane-diethyl ether at 25 deg C the presence of water gave all partially methylated methyl α-D-hexopyranosides which differ in number and position of methyl substitution.The presence electrolytes, such as potassium or sodium phosphate, in the reaction medium enhanced the degree of methylation, resulting in preferential formation of tri-O-methyl derivatives of methyl α-D-hexopyranosides.