Synthesis of 2,3-di-O-glycosyl derivatives of methyl α- and β-d-glucopyranoside

Nifant'ev, Nikolay E.; Amochaeva, Vera Yu.; Shashkov, Alexander S.; Kochetkov, Nikolay K.

doi:10.1016/0008-6215(93)84002-n

Cited by 8 publications

(5 citation statements)

References 22 publications

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“…The disaccharide was deprotected via treatment by sodium in liquid ammonia, consecutive re- O -acetylation with acetic anhydride in pyridine, and finally O -deacetylation with sodium methoxide in methanol. Purification using gel permeation chromatography gave the target disaccharide, having NMR spectral data in complete agreement with those previously published . Atoms in the terminal residue are denoted by a prime, and in the O -methyl residue, the atoms are unprimed.…”

Section: Methodssupporting

confidence: 77%

“…Purification using gel permeation chromatography gave the target disaccharide, having NMR spectral data in complete agreement with those previously published. 44 Atoms in the terminal residue are denoted by a prime, and in the O-methyl residue, the atoms are unprimed. The torsion angles at the glycosidic linkage between the sugar residues are denoted by φ ) H1′-C1′-O4-C4 and ψ ) C1′-O4-C4-H4.…”

Section: Resultsmentioning

confidence: 99%

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Determination of the Conformational Flexibility of Methyl α-Cellobioside in Solution by NMR Spectroscopy and Molecular Simulations

et al. 2004

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The conformational flexibility of methyl α-cellobioside in water and dimethyl sulfoxide solutions was investigated by 1D 1H,H T-ROESY experiments. In combination with molecular dynamics simulations, effective proton−proton distances could be derived using experimentally determined cross-relaxation rates. An anti-ψ-conformational state was present in both solvents confirming a previous flexibility hypothesis at this torsion angle. In water solution, an anti-φ-conformational state was also detected and quantified. These results show that already at the disaccharide level a large flexibility is present at the glycosidic linkage. In addition to the syn-conformation which is present to ∼93% for the title compound in water solution, the minor anti-φ- and anti-ψ-conformational states are populated to ∼2% and ∼5%, respectively.

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Section: Methodssupporting

confidence: 77%

Section: Resultsmentioning

confidence: 99%

Determination of the Conformational Flexibility of Methyl α-Cellobioside in Solution by NMR Spectroscopy and Molecular Simulations

et al. 2004

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“…The PClB protecting group could be cleaved in a two-step process by first converting the Cl to OCH 3 in a palladium catalyzed reaction as described, followed by a standard PMB-deprotection step. Direct conversion by catalytic hydrogenolysis has been described previously for the PClB protecting group, but not for the PCNB counterpart. To confirm previous results for the PClB removal and explore the possibility of catalytic hydrogenolysis as a means to remove the PCNB group, reactions were carried out on the menthyl glucosides 35 and 36 .…”

Section: Resultsmentioning

confidence: 99%

Remote Electronic Effects by Ether Protecting Groups Fine-Tune Glycosyl Donor Reactivity

2016

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It was established that para-substituted benzyl ether protecting groups affect the reactivity of glycosyl donors of the thioglycoside type with the N-iodosuccinimide/triflic acid promoter system. Having electron donating p-methoxybenzyl ether (PMB) groups increased the reactivity of the donor in comparison to having electron withdrawing p-chloro (PClB) or p-cyanobenzyl ether (PCNB) protecting groups, which decreased the reactivity of the glycosyl donor relative to the parent benzyl ether (Bn) protected glycosyl donor. These findings were used to perform the first armed-disarmed coupling between two benzylated glucosyl donors by tuning their reactivity. In addition, the present work describes a highly efficient palladium catalyzed multiple cyanation and methoxylation of p-chlorobenzyl protected thioglycosides. The results of this paper regarding both the different electron withdrawing properties of various benzyl ethers and the efficient and multiple protecting group transformations are applicable in general organic chemistry and not restricted to carbohydrate chemistry.

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“…The synthesis of the C-4 II modified disaccharide 24 is outlined in Scheme 1. Coupling of imidate 25 [24] with the methyl glycoside (26) [25] gave disaccharide 27 (85 % yield), and subsequently, octaacetate 28 and fluoride 29 were prepared prior to deacetylation. Condensation of the donor 24 with the b-d-glucoside 2 and subsequent acetylation of the reaction products gave rise to trisaccharide 30 in 65 % yield (Table 1 entry 9).…”

Section: Entry Donormentioning

confidence: 99%

“…The solution was subjected to workup (CH 2 Cl 2 ) and flash chromatography (40 ± 60 % EtOAc/petrol ether) to give the fluoride (21) . A small sample of the trisaccharide was treated with Ac 2 O/pyridine/N,Ndimethylaminopyridine (12 h) and then subjected to workup (CHCl 3 ) and flash chromatography (50 ± 70 % EtOAc/petrol ether) to yield p-nitro- (27): Freshly activated molecular sieves (powdered 4 ä, 500 mg) was added to a solution of a-d-galactosyl trichloroacetimidate (25) [24] (1.04 g, 2.1 mmol) and alcohol 26 [25] (604 mg, 1.6 mmol) in CH 2 Cl 2 (25 mL), and the combined mixture stirred (RT, 15 min). TMSOTf (30 mL) was added dropwise with continued stirring (10 min), followed by Et 3 N (200 mL).…”

mentioning

confidence: 99%

Synthesis of Complex Oligosaccharides by Using a Mutated (1,3)‐β‐D‐Glucan Endohydrolase from Barley

Fairweather

Hrmová

Rutten

et al. 2003

Chemistry A European J

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Complex oligosaccharides with newly formed (1,3)-beta-glycosidic linkages were obtained in good to excellent yields when substituted or unsubstituted alpha-laminaribiosyl fluorides, acting as donors, were condensed onto mono- and disaccharide beta-D-hexopyranoside acceptors by using a (1,3)-beta-D-glycosynthase. These linear and branched (1,3)-beta-linked oligosaccharides could prove to be important in a range of medical, pharmaceutical, and agricultural applications. Furthermore, the observation that the (1,3)-beta-D-glucan glycosynthase accommodates (1,3)-, (1,4),- and (1,6)-beta-oligosaccharides in its acceptor subsites suggests novel, yet unexpected physiological roles for the wild type (1,3)-beta-D-glucan endohydrolase from higher plants.

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Synthesis of 2,3-di-O-glycosyl derivatives of methyl α- and β-d-glucopyranoside

Cited by 8 publications

References 22 publications

Determination of the Conformational Flexibility of Methyl α-Cellobioside in Solution by NMR Spectroscopy and Molecular Simulations

Determination of the Conformational Flexibility of Methyl α-Cellobioside in Solution by NMR Spectroscopy and Molecular Simulations

Remote Electronic Effects by Ether Protecting Groups Fine-Tune Glycosyl Donor Reactivity

Synthesis of Complex Oligosaccharides by Using a Mutated (1,3)‐β‐D‐Glucan Endohydrolase from Barley

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