Organometallic derivatives of sugars

Stable organometallic derivatives of glucose were prepared either by treatment of 2,3,4,6-tetra-O-acetyl-1-thio-β-D-glucopyranose with organometallic hydroxides R₃ MOH and oxides R₂ MO or by the reaction between 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide with R₃SnSLi.     

Electron ionization mass spectra and their reproducibility for trialkylsilylated derivatives of organic acids, sugars and alcohols

Mass spectra of trialkylsilyl derivatives of fatty acids, dicarboxylic acids, hydroxyacids, oxoacids, sugars, amino acids and alcohols were obtained. Amino acids were analyzed as tert-butyldimethylsilyl derivatives; all other model compounds were analyzed as trimethylsilyl derivatives. Reproducibility of the electron ionization (EI) mass spectra for the derivatives obtained was discussed. It was shown that, for many investigated derivatives, composition of the respective mass spectra depended greatly on ion source contamination. The trimethylsilylated alpha-tocopherol mass spectrum composition was most significantly influenced by ion source contamination. This compound can be used to test ion source contamination.     

Simple synthesis of O-benzylidene derivatives of sugars

Conclusions A convenient method was proposed for obtaining cyclic O-benzylidene acetals of sugars.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2160–2161, September, 1977.     

Isothiocyanato derivatives of sugars in the stereoselective synthesis of spironucleosides and spiro-C-glycosides

A stereocontrolled synthesis of pyranoid and furanoid spironucleosides and spiro-C-glycosides (d-ribo and d-arabino configurations) of oxazolidines, oxazolines and perhydrooxazines via isothiocyanato sugar derivatives is reported. The intermediate isothiocyanates are prepared from sugar spiroketals by stereoselective opening of the acetal ring with trimethylsilyl N- and C-nucleophiles, and later formation of the isothiocyanato group.     

Tandem acetalation-acetylation of sugars and related derivatives with enolacetates under solvent-free conditions

Molecular iodine catalyzes acetalation and acetylation of reducing sugars and sugar glycosides with stoichiometric amounts of enol acetates under solvent-free conditions, thereby facilitating the synthesis of various types of orthogonally protected sugar derivatives in short time and good yields. The outcome of the reaction can be controlled by variation in temperature. Thus at lower temperature, it is possible to obtain the acetonide acetate as a single product whereas peracetate is the major product at higher temperature.     

Heteroadamantanes and their derivatives

5,7,-Dinitro-6,6-dimethyl-1,3-diazaadamantane was synthesized by condensation of 1,3-dinitro-2,2-dimethyl-propane with hexamethylenetetramine. Like the previously prepared 5,7-dinitro-1,3-diazaadamantane, it is converted into the corresponding diamino derivative with hydrazine hydrate in the presence of a nickel catalyst, and the diamino compounds gave the 5,7-dibromo derivatives on treatment with sodium nitrite in conc. HBr. The latter were converted to 6,6-dimethyl-1,3-diazaadamantane and 1,3-diazaadamantane on treatment with hydrazine hydrate in the presence of nickel catalyst in ethanol.For Communication 18 see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 230–233, February, 1993.     

Heteroadamantanes and their derivatives

1-p-nitrophenyl-3,6-diazahomoadamantane and 1-p-nitrophenyl-3,6-diazahomoadamantan-9-one were obtained by nitration of 1-phenyl-3,6-diazahomoadamantane and 1-phenyl-3,6-diazahomoadamantan-9-one with a mixture of potassium nitrate and sulfuric acid; 1-p-nitrophenyl-3,6-diazahomoadamantan-9-one was reduced with sodium borohydride to 1-p-nitrophenyl-3,6-diazahomoadamantan-9-ol. It was found that the nitro groups of these nitrophenyldiazahomoadamantanes were reduced to amino groups by heating with hydrazine hydrate without a catalyst. 1-p-Aminophenyl-3,6-diazahomoadamantan-9-one was obtained by reduction of nitrophenyl-azahomoadamantanone with tin in sulfuric acid, and 9-amino-1-p-aminophenyl-3,6-diazahomo-adamantane was obtained by reduction of its oxime with a nickel—aluminum alloy in water—base medium.See [1] for 17.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1257–1261, September, 1992.     

Polymethylenepolynitramines and their derivatives

Hitherto unknownN-fluoro-substituted polymethylenepolynitramines were synthesized by fluorinating the respective polymethylenepolynitramines with elemental fluorine in anhydrous acetonitrile.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2174–2176, December, 1994.     

Heteroadamantanes and their derivatives

6-Cyano-1,3-diazaadamantan-6-ols and- 9-cyano-3,6-diazahomoadamantan-9-ols, whose reaction with ammonia forms the corresponding 6-cyano-6-amino-1,3-diazaand 9-cyano-9-amino-3,6-diazahomoadamantanes, were prepared by the exchange reaction of 1,3-diazaadamantan-6-ones and 3,6-diazahomoadamantan-9-ones with acetone cyanohydrin. When heated with ammonium carbonate, spirohydantoins were directly obtained from the former compounds and from the initial ketones by Bucherer—Bergs synthesis.See [1] for Communication 15.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 648–652, May, 1992.     

Chromatography of functionalized liposomes and their components

The antitumour drug 1-beta-D-arabinofuranosylcytosine (ara C) was acylated by means of oleic acid anhydride, resulting in the prodrug N4-oleoyl-ara C. Together with a lipophilic biotin derivative, this lipophilic prodrug was incorporated into the bilayer membrane of unilamellar liposomes prepared by means of the detergent dialysis method. On addition of these biotinylated prodrug-liposomes to an excess of avidin, biotin residues were complexed with avidin. The unreacted avidin was removed by chromatography on the Ultrogel AcA-22 column. The prodrug-liposome-avidin complex was coupled to biotinylated monoclonal antibodies through the free binding sites of the immobilized avidin. Unreacted antibodies were removed by chromatography on an Ultrogel AcA-22 column. In vitro, the liposome-antibody complexes selectively bound to cells which were recognized by the monoclonal antibodies linked to the liposomes. For this reason, a promising strategy towards a specific chemotherapy of cancer is expected.     

Chromatography of organic derivatives of group IVB elements

Chromatographic aspects of the analysis of Group IV organometallic derivatives are reviewed. The emphasis is towards gas and liquid chromatography.     

1,4-Benzodiazepines and their derivatives

A series of compounds of the merocyanine dye type was obtained by the reaction of 1-acetyl-1,3-dihydro-2H-1,4-benzodiazepin-2-ones and 1,3-dihydro-2H-1,4-benzodiazepine-2-thiones with 2-methylmercapto-3-ethylbenzothiazolium tosylate, 2-methylmercapto-3,4,5-trimethylthiazolium bromide, 2-methylmercapto-3-methyl-5-phenyloxazolium methosulfate, and 1,3,3-trimethyl-2-formylmethyleneindoline. The hydrogen atoms of the methylene group of the 1-unsubstituted and 1-alkyl-substituted 1,3-dihydro-2H-1,4-benzodiazepin-2-ones are of low mobility, and the indicated compounds do not undergo condensation reactions with electrophilic agents.See [6] for communication VI.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 992–994, July, 1971.     

Simultaneous GC-MS quantitation of o-phosphoric, aliphatic and aromatic carboxylic acids, proline, hydroxymethylfurfurol and sugars as their TMS derivatives: In honeys

Summary A GC-MS procedure is described for the simultaneous quantitatation of the minor and major constituents of honeys, as their trimethylsilyl derivatives, from one solution, by one injection. Selected minor components (aliphatic and aromatic carboxylic acids, members of various homologous series, together with o-phosphoric acid, proline and hydroxymethylfurfurol), have been determined on the basis of their characteristic fragment ions, in the presence of extremely high excess of honeysaccharides. Selective fragmentation of these minor compounds in the ion trap detector provided possibilities for distinguishing them. The method permitted the simultaneous quantitation of o-phosphoric, malic, shikimic, citric/isocitric, quinic, margaric, oleic and stearic acids, hydroxymethylfurfurol and proline with the extremely high sugar contents of honeys (fructose, glucose, galacturonic acid, inositol, sucrose, trehalose, turanose, maltose, gentiobiose, isomaltose, raffinose, erlose, melezitose, maltotriose, panose, isomaltotriose) and allowed the fast evaluation of sugar and acid constituents of fifteen honeys from various floral and geological origin. Results revealed that (i) the minor components varied in the concentration range of 0.0001 to 0.43%, and, (ii) together with the saccharides of honeys made up the total of identified and determined constituents from 87.8% to 98.5%. Quantitative evaluation of the minor constituents was performed on the basis of their selective fragment ion values with an average reproducibility of 6.7% (RSD). Presented at: Balaton Symposium on High-Performance Separation Methods, Siófok, Hungary, September 3–5, 1997     

Capillary column gas chromatographic identification of sugars in honey as trimethylsilyl derivatives

A method for identifying carbohydrates (mono-, di- and trisaccharides) in honey is presented. It is based on the separate preparation of both trimethylsilyl ethers and oxime trimethylsilyl ethers of the sugars followed by their gas chromatographic separation on a fused-silica capillary column coated with OV-101 using temperature programming. From the two chromatograms, the number of peaks given by each derivatized sugar, their relative retention times and peak-area ratios are used for identification. The identities of two unidentified trisaccharide peaks are considered. Quantitative applications to honey sugar analysis are discussed.