10503-93-2

Upstream product

• 69558-13-0 methyl 4-O-benzyl-3-O-methyl-α-L-rhamnopyranoside 
• 74050-68-3 methyl 2,4-di-O-benzyl-3-O-methyl-α-L-rhamnopyranoside 
• 186581-53-3 diazomethane 
• 14917-55-6 methyl 6-deoxy-α-L-mannopyranoside 
• 74-88-4 methyl iodide 
• 157889-68-4 2,4-di-O-benzyl-α-L-rhamnopyranoside 
• 1192-62-7 1-(2-furyl)-1-ethanone 
• 40246-38-6 methyl-2,3,6-tridesoxy-α-L-erythro-hex-2-enopyranoside 
• 3615-41-6 L-Rhamnose 
• 25019-69-6 methyl 4-O-benzyl-α-L-rhamnopyranoside 
• 69850-47-1 (2R,3R,4R,5R,6S)-3,5-Bis-benzyloxy-2-methoxy-6-methyl-tetrahydro-pyran-4-ol 
• 61199-76-6 methyl 4-O-benzyl-endo-2,3-O-benzylidene-α-L-rhamnopyranoside 
• 67-56-1 methanol 
• 18276-53-4 1-(trimethylsilyl)-1H-pyrrole 

Downstream Products

• 523-74-0 O³-methyl-6-deoxy-D-altrose 
• 112047-81-1 O³-methyl-D-ribo-6-deoxy-[2]hexosulose-bis-phenylhydrazone 
• 56083-41-1 methyl 2,4-di-O-acetyl-3-O-methyl-α-L-rhamnopyranoside 

Relevant academic research and scientific papers

A single-step synthesis of methyl 3-O-methyl-α-D-manno-, -α-D-galacto-, -α-L-rhamno-, and -α-L-fuco-pyranoside

Mycobaterial polysaccharides and antibiotics often contain some partially methylated monosaccharide units. Thus, 3-O-methylated methyl glycopyranonsides are useful as authentic samples for structure determinations, or as intermediates for the synthesis of some natural products. Several methods have been developed for the synthesis of the 3-methyl ethers of methyl glycopyranosides.

Asymmetric synthesis of methyl 6-deoxy-3-O-methyl-α-l-mannopyranoside from a non-carbohydrate precursor

A novel method is reported for preparing methyl 6-deoxy-3-O-methyl-α- l-mannopyranoside (1) by asymmetric synthesis, using 2-acetylfuran (2), a non-chiral simple molecule, as the starting material and achieving high yields via (S)-1-(2-furyl)ethanol and (

Mandelalides A-D, cytotoxic macrolides from a new Lissoclinum species of South African tunicate

Mandelalides A-D are variously glycosylated, unusual polyketide macrolides isolated from a new species of Lissoclinum ascidian collected from South Africa, Algoa Bay near Port Elizabeth and the surrounding Nelson Mandela Metropole. Their planar structures were elucidated on submilligram samples by comprehensive analysis of 1D and 2D NMR data, supported by mass spectrometry. The assignment of relative configuration was accomplished by consideration of homonuclear and heteronuclear coupling constants in tandem with ROESY data. The absolute configuration was assigned for mandelalide A after chiral GC-MS analysis of the hydrolyzed monosaccharide (2-O-methyl-α-l-rhamnose) and consideration of ROESY correlations between the monosaccharide and aglycone in the intact natural product. The resultant absolute configuration of the mandelalide A macrolide was extrapolated to propose the absolute configurations of mandelalides B-D. Remarkably, mandelalide B contained the C-4′ epimeric 2-O-methyl-6- dehydro-α-l-talose. Mandelalides A and B showed potent cytotoxicity to human NCI-H460 lung cancer cells (IC50, 12 and 44 nM, respectively) and mouse Neuro-2A neuroblastoma cells (IC50, 29 and 84 nM, respectively).

Regioselective methylation of methyl glycopyranosides with diazomethane in the presence of transition-metal chlorides and of boric acid

Partial methylation of the methyl pyranosides of a number of pentoses, hexoses, 6-deoxyhexoses, methyl uronates and their methyl ethers with diazomethane in the presence of transition-metal chlorides and boric acid was studied. It was found for methyl glycosides of pentoses and 6-deoxyhexoses that tin(II), antimony(III), and titanium(IV) chlorides as well as boric acid promoted substitution mainly of OH-3, but with cerium(III) and zinc(II) salts mainly substitution of OH-2 was observed. Methylation of methyl β-l-rhamnopyranoside demonstrated higher reactivity of OH-2 in all cases. The methylation of methyl glycosides of hexoses in the presence of tin(II), antimony(III) and cerium(III) chlorides gave mainly 3-methyl ethers. The 3-methyl ethers, which are not involved in further complexation, accumulated up to 50-80% of the reaction mixture (95-100% of monomethyl ether fraction). Convenient preparative syntheses of methyl ethers for a number of sugars are suggested. Copyright (C) 1999 Elsevier Science Ltd.

Synthesis of acofriose, a constituent sugar of the lipopolysaccharide of a smooth strain of Pseudomonas syringae pv. phaseolicola, race 2

The sugar composition of the lipopolysaccharide (LPS) of a smooth strain of Pseudomonas syringae pv. phaseolicola, race 2 has been determined.Rhamnose, fucose, acofriose(3-O-methyl-L-rhamnose) and glucose have been found to be the main constituent of the sugar chain of the LPS.For unequivocal characterization of acofriose by chromatographic technique, it has been synthesized by a convenient procedure in two steps.

An n.m.r. and conformational analysis of the terminal trisaccharide from the serologically active glycolipid of Mycobacterium leprae in different solvents

The 1H- and 13C-n.m.r. spectra of allyl 2-O--3-O-methyl-α-L-rhamnopyranoside (3), a glycoside of the terminal trisaccharide found in the phenolic glycolipid I from Mycobacterium leprae, and those of the two component disaccharides, allyl 4-O-(3,6-di-O-methyl-β-D-glucopyranosyl)-2,3-di-O-methyl-α-L-rhamnopyranoside (1) and allyl 2-O-(2,3-di-O-methyl-α-L-rhamnopyranosyl)-3-O-methyl-α-L-rhamnopyranoside (2) have been assigned completely by 1D and 2D techniques.The preferred conformations, determined by chemical shift and n.O.e. studies, were different in D2O, CD3OD, and CDCl3.The preferred conformation of 3 accorded with the results of hard-sphere exo-anomeric (HSEA) calculations.

REGIOSELECTIVE ENHANCEMENT OF THE NUCLEOPHILICITY OF THE HYDROXYL GROUPSIN METHYL α-L-RHAMNOPYRANOSIDE BY COMPLEXATION WITH TIN(II) CHLORIDE

A tentative mechanism for complexanation, and a possible model of a tin(II)chloride-methyl glycoside intermediate complex, have been established largely from analysis of methyl ethers formed on methylation of methyl α-L-rhamnopyranoside and its monomethyl ethers by diazomethane in the presence of a catalytic amount of tin(II) chloride in selected solvents.The complex is mainly formed through displacement of molecules of the donor solvent coordinated to a tin(II) atom by the favorably cis-disposed, hydroxyl groups of the sugar moiety.The spatiel arrangement of the hydroxyl groups plus the distribution of atomic charges at the individual oxygen atoms of hydroxyl groups of the methyl glycoside were found to be the main factors responsible for the selectivity observed.The effect of selected solvents on the stability and/or ability to participate in the formation of the foregoing intermediate complex could not be satisfactorily clarified.