Some Open-Chain Derivatives of Glucose and Mannose

Curtis, E. J. C.; Jones, J. K. N.

doi:10.1139/v60-126

Cited by 18 publications

(8 citation statements)

References 6 publications

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“…85 The differences in hydration rates of CH,*CHO, CD,-CHO, CH,-CDO, and CD,CDO are relatively small and compatible only with secondary isotope effects.B6 On the other hand, the ratios of the rates of hydration and dehydration in water to those in D20 are very similar to those found for the mutarotation of glucose. 86 The ionisationconstant ratio of acetaldehyde hydrate in water and D20 is about 4.5, which is understandable since the hydrate is CH,*CH(OH), in H,O and CH,*CH(OD) in D20.a6 The generally accepted dehydration mechanism, with water acting as general base, would lead to the conclusion that the experimental rate ratio, KHIO/KD,O -3.8 , arises mainly from the pre-equilibrium step. However, a rate ratio of 3.8 is not inconsistent with water acting as a general acid.g6 Similar conclusions have been reached with respect to the mutarotation of glucose and tetra-0-methylglucose in H20 and D20.…”

Section: Olefin + H30+mentioning

confidence: 99%

“…84 The Grignard reagent itself is best represented as a dialkylmagnesiummagnesium halide complex.86 Light-metal alkoxides have been shown to catalyse the reactions between magnesium and many organic halides, e.g., chlorobenzene. 86 The preparation and uses of diazoketones have been reviewed,87 and fluoroboric acid has been shown to be an efficient catalyst for the homologation of ap-unsaturated ketones with diazomethane.88 Further use of a-acetoxyacrylonitrile as a dienophile in a Diels-Alder reaction has been rep0rted.8~…”

Section: Oh Ohmentioning

confidence: 99%

“…Branched-chain acids such as (68), oxidised by permanganate in acetone solution, provide a series of branched-chain acids, one methyl ketone, and a series of unbranched acids which clearly identify the structure. 86 Oxidation with chromic acid occurs preferentially at the tertiary carbon atom in (68), so that fewer oxidative fragments have to be recogni~ed.~' Certain difficulties in determining the structure of polyethenoid acids are overcome in a new procedure in which the acid is only partially oxidised by performic acid and then hydrogenated to a mixture of saturated dihydroxy-acids. These are degraded to a series of mono-and di-basic acids which indicate the chain-length of the original acid and the position of each double bond.…”

Section: + -mentioning

confidence: 99%

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Organic chemistry

Stevens¹,

Chapman²,

Pocker³

et al. 1960

Annu. Rep. Prog. Chem.

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Section: Olefin + H30+mentioning

confidence: 99%

Section: Oh Ohmentioning

confidence: 99%

Section: + -mentioning

confidence: 99%

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Organic chemistry

Stevens¹,

Chapman²,

Pocker³

et al. 1960

Annu. Rep. Prog. Chem.

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“…Copper can also be a versatile catalyst and promote reductions (hydrosilylation of ketones [40]) or oxidations (cleavage/oxidation of benzylidene acetals [41]). As last examples, copper catalyses the protection/deprotection transformations of important functional groups such as the formation of isopropylidene acetals [42], the deprotection of thioacetals, and selective ester hydrolysis [43].…”

Section: Introductionmentioning

confidence: 99%

Bio-based Catalysts from Biomass Issued after Decontamination of Effluents Rich in Copper—An Innovative Approach towards Greener Copper-based Catalysis

2019

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The abundance of Cu-contaminated effluents and the serious risk of contamination of the aquatic systems combine to provide strong motivating factors to tackle this environmental problem. The treatment of polluted effluents by rhizofiltration and biosorption is an interesting ecological alternative. Taking advantage of the remarkable ability of the selected plants to bioconcentrate copper into roots, these methods have been exploited for the decontamination of copperrich effluents. Herein, we present an overview on the utility of the resulted copper-rich biomass for the preparation of novel bio-sourced copper-based catalysts for copper-mediated reactions: from the bioaccumulation of copper in plant, to the preparation and full analysis of the new Eco-Cu catalysts, and their application in selected key reactions. The hydrolysis of a thiophosphate, an Ullmanntype coupling leading to N- and O-arylated compounds, and a CuAAC “click” reaction, all performed under green and environmentally friendly conditions, will be described.

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“…2-0-Methyl-D-mannose was synthesized by the method of Curtis and Jones (8), except that the diethyl dithioacetal was used. This ether was also prepared by the method of Aspinall and Zweifel (9).…”

mentioning

confidence: 99%

Methylation of Sugar Dithioacetals: V. D-Mannose Diethyl Dithioacetal

Dutton¹,

Tanaka²

1963

Can. J. Chem.

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Partial rnethylation of D-mannose diethyl dithioacetal in tetrahydrofuran with methyl iodide and silver oxide yielded 2-, 3-, and 6-0-methyl-D-mannose in the ratio of 12:1:1, respectively. The major cotnponent, 2-0-methyl-D-mannose, was characterized as the phen) 1-hydrazone and the other isomers identified by electrophoresis. The Mg values of these mono-0-methyl ethers were recorded.In Part I of this series it was demonstrated that various sugar dithioacetals could be successfully methylated in tetrahydrofuran with methyl iodide and silver oxide (I). Subsequent papers have reported the nature of the mono-0-methyl ethers obtained by partial methylation of the diethyl dithioacetals of L-arabinose (2), D-galactose (3), and D-xylose (4). The present paper reports the mono-0-methyl ethers obtained by methylation of D-mannose diethyl dithioacetal under similar conditions and is a continuation of our study on the relative reactivities of hydroxyl groups in sugar dithioacetals.Preparation of D-mannose diethyl dithioacetal by Fischer's method (5) was found to give unreliable results since on several occasions the crude product decomposed on washing with ice water. I t was found preferable to neutralize with barium carbonate and dilute with lnethanol whence the dithioacetal could be obtained by evaporation of the filtered solution.The drthioacetal was shaken in tetrahydrofuran a t room temperature with an appropriate amount of silver oxide and methyl iodide to give a reasonable yield of the mono-0-methyl ethers, after hydrolysis. The mono-and di-0-methyl ethers were separated from the unchanged and poly-0-methylated D-mannoses by chromatography in butanonewater azeotrope.Electrophoresis in 0.05 M borate showed that the mixture of mono-0-methyl ethers contained three isomers, one of which was predominant judging from the size and intensity of the spots. These three components had M , values of 0.38, 0.54, and 0.63, and were shown to be 2-, 3-, and 6-0-methyl-D-mannose, respectively, by concurrent electrophoretic examination with synthetic samples of these isomers. 2-0-hIethyl-D-mannose gave the strongest and largest spot, and the others were weak and small. The mixture of di-0-methyl ethers, which might contain the 5-0-methyl ether, was also examined by electrophoresis but only a very slowly migrating component was detected, suggesting no 5-Omethyl ether was present.The phenol -sulphuric acid method (6) of quantitative analysis on the mixture of mono-0-methyl-D-mannoses gave a ratio of 12:l:l for 2-, 3-, and 6-0-methyl-D-mannose, respectively.The mixture of mono-0-methyl-D-mannoses was separated on Whatman No. 3MM paper by electrophoresis and the area corresponding t o the 2-0-methyl-D-mannose was extracted with water. The extract was deionized and evaporated to a sirup, which was 'Present address:

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Some Open-Chain Derivatives of Glucose and Mannose

Cited by 18 publications

References 6 publications

Organic chemistry

Organic chemistry

Bio-based Catalysts from Biomass Issued after Decontamination of Effluents Rich in Copper—An Innovative Approach towards Greener Copper-based Catalysis

Methylation of Sugar Dithioacetals: V. D-Mannose Diethyl Dithioacetal

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