Fungal hydroxylation of ethyl benzene and derivatives

The fungus $\text{Mortierella isabellina}$ converts ethyl benzene and a number of parasubstituted derivatives to the corresponding optically active 1-phenylethanols with enantiomeric excesses between 5 and 40%. Hydrogen removal from the substrate preceeds product formation and is stereochemically independent of it.     

Functions of class Lip(α, p) and their Taylor mean

The object of this paper is to study the rapidity of convergence of the Taylor mean of the Fourier series of ƒ(x) when ƒ(x) belongs to the class Lip(α, p). We show that it is of Jackson order provided that a suitable integrability condition is imposed upon the function

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Alkyl ketoximes as analytical reagents: The chloroform extraction of the alkyl ketoxime complexes of palladium (II) chloride

Summary The syntheses of four symmetrical alkyl ketoxime complexes of palladium(II) chloride and a study of their extraction into chloroform from an aqueous-alcohol solution ofph 3.0 are described.

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Zusammenfassung Die Synthese vier verschiedener Komplexverbindungen von PdCl₂ mit symmetrischen Alkylketoximen wurde beschrieben. Deren Extrahierbarkeit mit Chloroform aus wäßrig-alkoholischer Lösung beiph 3,0 wurde untersucht.

     

Quinazolines and 1,4-benzodiazepines. LXXVIII Pyrazolo[1,5-a] [1,4]-benzodiazepines and Imidazo[1,5-a] [1,4]benzodiazepinones

The syntheses of novel 8-chloropyrazolo[1,5-a][1,4]benzodiazepines and of an imidazo-benzodiazepinone utilizing products from the nucleophilic substitution of fluorine in 2-fluoro-5-nitrobenzophenone ( 1 ) by pyrazole-3,5-dicarboxylic acid, dimethyl ester ( 2 ) and by 2-methyl-imidazole-4,5-dicarboxylic acid, diethyl ester ( 30 ) are described.     

Quantitative magnetic resonance imaging of urea and lysozyme in protein chromatography

Magnetic resonance imaging (MRI) techniques have been implemented to enable quantitative imaging of protein and urea within a 5 ml HiTrap size-exclusion chromatography desalting column, without introduction of contrast agents. One-, two- and three-dimensional images of urea injected at concentrations of 2, 4, 6 and 8 M were acquired. One-dimensional profiles of lysozyme at concentrations between 5 and 25 mg ml(-1) were also obtained. All data were accurate to within +/- 15% when compared to the known amount injected. Quantitative MRI elution profiles of both urea and lysozyme were then obtained in real-time during a desalting separation.     

A stereoselective synthesis of xylitol

Rel-(2S, 3R, 4R)- (6) and rel-(2R,3R,4R)- (7) 1,2,5-triacetoxy-3,4-epoxypentanes have been obtained in seven steps starting from cyclopentadiene. Both diastereoisomers afford xylitol pentaacetate (8) selectively upon epoxide cleavage with acetate ion. In the case of (6), rel-(1s,3R,4r,5S)-3,-bisacetoxymethyl-1-methyl-2,6,7-trioxabicyclo- [2.2.1]heptane (11) has been isolated and characterised as an intermediate in the reaction.     

The simultaneous spectrophotometric determination of iron and copper with disodium 3-hydroxy-4-[(6-methyl-2-pyridyl)azo] -2,7-naphtalenedisulfonate N-oxide

Microchimica Acta - The use of the title reagent for the simultaneous determination of iron and copper is described. The effects due to pH, time, reagent concentration and diverse ions are...     

Pyridine ketoximes as analytical reagents. XIX

Summary The spectrophotometric determination of traces of platinum with 2-pyridyl-2-thienyl-Z-ketoxime is described. Experimental parameters were evaluated and a study of diverse ion tolerance was carried out. Sensitivity was increased by the use of 4-cm cells. Beer's law was obeyed and the molar absorptivity at 473 nm was 7.11×10³.

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Zusammenfassung Die spektrophotometrische Bestimmung von Spuren Platin mit 2-Pyridyl-2-thienyl-Z-ketoxim wurde beschrieben. Die experimentellen Parameter wurden bewertet und die Toleranz gegen verschiedene Fremdionen ermittelt. Durch Verwendung von 4-cm-Küvetten wurde die Grenze der Bestimmbarkeit herabgesetzt. Das Beersche Gesetz ist gültig; die molare Extinktion beträgt 7,11·10³.

     

Extraktion des Kupfers als Poly?thylenglykol-Saccharinato-Cuprat(I) und die photometrische Bestimmung als Dibutylammonium-Carbonato-Cuprat(II)

Zusammenfassung Die Extraktion des Kupfers als Polyäthylenglykol-saccharinatocuprat(I) ermöglicht die Abtrennung von Kupfermengen ab 10 g aufwärts von Metallen bei den Verhältnissen CuBi PbZnCdCoFeAl bis 15000 2000015000100000400000150000 10⁶. Die auftretenden Fehler liegen allgemein unterhalb von 2%. Das extrahierte Kupfer wird entweder als Carbonatokomplex [Cu(CO₃)₂]^2– oder mit Rubeanwasserstoff photometrisch bestimmt. Niedrige Kupfergehalte in Stählen sind mit genügender Genauigkeit bestimmbar.Dem Fonds der chemischen Industrie danken wir für Unterstützung der Arbeit.