Synthesis Of Amino Sugars Research Articles

Inelastic electron tunnelling spectroscopy—V. The formation of molecules of bioevolutionary importance on an alumina surface

The alumina barrier of AlAlO x Pb tunnelling junctions have been exposed to aqueous ammonia, wet carbon monoxide gas and to aqueous formaldehyde vapour. The aqueous ammonia spectrum is assigned as an amino acid species produced from ammonia, water and atmospheric carbon dioxide. This spectrum fingerprints very closely with the tunnelling spectrum of a genuine sample of glycine. The role of atmospheric carbon dioxide is deduced from a spectrum of aqueous ammonia produced in the absence of carbon dioxide. The wet carbon monoxide spectrum and the aqueous formaldehyde spectrum have been produced by an infusion doping process. These spectra are assigned as a sugar-like polymer or a sugar formed on the alumina surface. A tunnelling spectrum of d(−)fructose has been produced to aid this assignment. The role of an inorganic template such as alumina in the original prebiotic synthesis of amino acids and sugars is considered.

Regio- and stereo-selective transformation of glycosides to amino-glycosides. Practical synthesis of amino-sugars, 4-amino-4-deoxy-D-galactose, 4-amino-4-deoxy-L-arabinose, 3-amino-3-deoxy-D-allose, 3-amino-3-deoxy-D-glucose, 3-amino-3-deoxy-D-ribose, 3-amino-3-deoxy-D-xylose, 2-amino-2-deoxy-D-mannose, and 5-amino-5-deoxy-D-glucose (nojirimycin).

One of the hydroxyl groups in glycosides was regio- and stereo-selectively converted to an amino group as follows. A glycoside was regioselectively converted to an oxo-glycoside by bis-tributyltin oxide-bromine oxidation. Oximation of this and reduction of the resulting oxime in a stereoselective manner gave an amino-glycoside in a satisfactory yield.By application of this method, 4-amino-4-deoxy-D-galactose, 4-amino-4-deoxy-L-arabinose, 3-amino-3-deoxy-D-allose, 3-amino-3-deoxy-D-glucose, 3-amino-3-deoxy-D-ribose, 3-amino-3-deoxy-D-xylose, and 2-amino-2-deoxy-D-mannose were synthesized in satisfactory yields from D-xylose or D-glucose as their α- or β-methyl glycosides. The method also provided a practical synthetic route to nojirimycin (5-amino-5-deoxy-D-glucose), a glucosidase-inhibitory antibiotic, from D-glucose.

Boron Mobility and Nutrition in Broccoli (Brassica oleracea var. italica

Broccoli (Brassica oleracea var. italica cv Premium Crop) plants were germinated in soil, transferred to vermiculite three weeks later and grown in the glasshouse, then either supplied continuously with boron levels ranging from 0.0 (deficient) to 12.5 (toxic) mg l−1 of nutrient solution or transferred from 2.5 to 0.0 mg B l−1 at the initiation of inflorescence development. At commercial maturity the concentrations of various inorganic and organic solutes in phloem exudates and xylem saps, as well as plant characteristics and elemental composition of the various plant parts, were determined. Under deficient B levels leaf midrib and stem corkiness were evident, together with signs of stem pith breakdown, symptoms which resemble the initiation of the hollow stem disorder. The xylem sap B concentration declined by about 50 % when B was not supplied or was removed after a period of adequate supply; the phloem concentration was unaffected. Also, the decreasing B concentration gradients from mature transpiring tissues to young developing sinks disappeared. Therefore, it is concluded that when B is deficient, it is retranslocated from source leaves in the phloem stream supplying the developing leaves and inflorescence. The data also suggested that at toxic levels B undergoes extensive lateral transfer, probably from xylem to xylem, thereby enhancing the B concentration of developing sinks. The B regime influenced dry-matter partitioning, retranslocation of some elements, and the synthesis and distribution of amino acids and sugars, reflecting the general nature of B involvement in plant processes.

ChemInform Abstract: A New Method for Diastereoselective Amination in Acyclic Systems and Total Synthesis of Amino Sugars

ChemInform Abstract: A New Method for Diastereoselective Amination in Acyclic Systems and Total Synthesis of Amino Sugars

Synthesis of novel branched-chain amino sugars: methyl l-sibirosaminide and N-acylkansosamine

Methyl l-sibirosaminide and N-acylkansosamine were synthesized via the same intermediate, methyl 4-amino-4,6-dideoxy-2,3- O-isopropylidene-3- C-methyl-α- l-mannopyranoside ( 7), from l-rhamnose in 7 and 10 steps, respectively. Conversion of 7 into the title compounds was performed by N-methylation or N-(2-methoxypropanoyl)ation followed by appropriate derivatization.

ChemInform Abstract: Syntheses of Biologically Important Carbohydrates. Part 33. Syntheses of Unsaturated Amino Sugars and Aminoalkyl‐branched Carbohydrates via Sigmatropic Rearrangement of Trichloroacetimidates.

AbstractDas Pyranosid (I) läßt sich auf dem beschriebenen Weg in das Trichloracetimidat (IIIa) überführen.

Applications of N‐Sulfinyl Dienophile Diels‐Alder Cycloadditions to Synthesis of Unusual Amino Sugars

AbstractThe amino sugar moieties of staurosporine and nogalarol have been stereospecifically synthesized by a strategy utilizing N‐sulfinyl Diels‐Alder chemistry.

A New Efficient Synthesis of Amino Sugars Utilizing Ring Cleavage of Oxazole Skeletons

A New Efficient Synthesis of Amino Sugars Utilizing Ring Cleavage of Oxazole Skeletons

A new simple synthesis of amino sugar β- d-glycosylamines

A new simple synthesis of amino sugar β- d-glycosylamines

Synthesis of amino sugars via isoxazolines: Nitrile oxide-furan adducts as key intermediates in the isoxazoline route towards novel amino sugar derivatives

New variations for 1,3-dipolar nitrile oxide cycloadditions to reluctant dipolarophiles furan and 2-methylfuran are presented. The furoisoxazoline adducts 6 and 7 are shown to represent highly advanced, yet versatile precursors for derivatives of novel C 6 and C 7 amino sugar derivatives, accessible by subsequent highly stereoselective modification (addition of HO/OCH 3 or HO/OH) and/or LiAlH 4 reduction.

Stereoselection in acyclic systems. The synthesis of amino sugars via nitrone cycloadditions

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStereoselection in acyclic systems. The synthesis of amino sugars via nitrone cycloadditionsPhilip DeShong, C. Michael Dicken, Joseph M. Leginus, and Robert R. WhittleCite this: J. Am. Chem. Soc. 1984, 106, 19, 5598–5602Publication Date (Print):September 1, 1984Publication History Published online1 May 2002Published inissue 1 September 1984https://doi.org/10.1021/ja00331a033RIGHTS & PERMISSIONSArticle Views423Altmetric-Citations97LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (633 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

Isoxazolines‐Key Intermediates For Syntheses of Some Naturally Occuring Amino Compounds

Abstract[3+2]‐Cycloaddition of nitrile oxides with alkenes, modification of isoxazoline intermediates, and subsequent cleavage give rise to a variety of functionalized acyclic structures. Each step may be used to diastereoselectively increase the number of chiral centres. Application of this concept to the synthesis of natural amino polyols, amino sugars and hydroxy amino acids is discussed.

ChemInform Abstract: Synthesis of Amino Sugars from Tri‐O‐acetyl‐D‐glucal via Epoxides.

AbstractAus dem Glucal (I) wird auf dem im Formelschema angegebenen Weg das D‐Mannopyranosid‐epoxid (IV) hergestellt, aus dem über das Azid (Va) der Aminozucker (Vb) zugänglich ist.

Syntheses of amino sugars from tri-O-acetyl-D-glucal via epoxides

Syntheses of amino sugars from tri-O-acetyl-D-glucal via epoxides

Addition photochimique de nitrènes sur les éthers vinyliques et sucres insaturés

The photochemical addition of nitrenes to cyclic vinylic ethers and unsaturated sugars, in the presence of alcohols, gave the products of alcoholysis of the aziridine intermediates. The reactivity and stereoselectivity of this addition is discussed. The application of this reaction to the synthesis of aminosugars is described.

Synthesis of amino sugars via isoxazolines the concept and one application: nitrile oxide/furan adducts

Aliphatic nitrile oxides cycloadd to furans to afford amino sugar precursors 1. Oxidation by m-chloroperbenzoic acid and/or LiA1H 4 reduction give rise stereoselectively to derivatives of the xylo and ido series, 2 – 4, with 3 to 5 adjacent chiral centres.

Addition des nitrenes sur les ethers vinyliques cycliques. Application a la synthese d'aminosucres.

The stereochemistry of the photochemical addition of nitrenes to cyclic vinylethers is reported. The application of this reaction to unsaturated sugars offers a synthesis of aminosugars.

Azidomercuration-demercuration : voie d'access aux amino-sucres

An improved method of azidomercuration with mercuric trifluoroacetate is described. Applied to unsaturated carbohydrates it provides a high yield synthesis of aminosugars. In the example herein reported, 80% regioselectivity and total stereospecificity are obtained.

Modification of amino acid and sugar transport in uncoupler-adaptedEuglena gracilis

Uncoupler-adapted Euglena gracilis have a greatly impaired capacity to take up and incorporate some exogenously supplied amino acids and sugars. The degree of inhibition varies widely from >90% in the case of valine or glucose to none in the case of histidine. The inhibition is due to a decreased activity of the transport mechanism itself and is not due to either a lesion in the control mechanism for endogenous amino acid or sugar synthesis nor to a direct inhibition of the transport mechanism by uncouplers. No preferential labeling of mitochondrial membranes by [14C]amino acids occurs during the process of adaptation, a time when no cell division occurs. Apparently, during the long time required for adaptation, there occurs no major modification of mitochondrial proteins which could explain the subsequent resistance to uncouplers.

Amino Sugars and N‐Glycosides by Oxyamination of Unsaturated Carbohydrate Derivatives

A useful process for the synthesis of numerous amino sugars results on application of the cis-oxyamination of olefins to unsaturated sugar derivatives such as (1). Chloramine-T serves as reagent, and OsO4 as catalyst.