Search results for "Furan"
showing 10 items of 667 documents
ChemInform Abstract: Reversal of Asymmetric Induction in Stereoselective Strecker Synthesis on Galactosyl Amine as the Chiral Matrix.
1989
Abstract The reversal of the direction of asymmetric induction in Lewis acid catalyzed Strecker synthesis using the 2,3,4,6-tetra-O-pivaloyl-β-D-galactopyranosyl amine 1 is described. In isopropanol or tetrahydrofuran 1 had given ( R )-diastereomers of the corresponding α-amino nitriles preferably. However, in chloroform in the presence of heterogeneous zinc chloride the same auxiliary alternatively leads to an excess of the ( S )-diastereomers.
Thermodynamisches verhalten, expansionskoeffizient und viskositätszahl von polystyrol in tetrahydrofuran
1968
Streulichtmessungen ergeben, das Polystyrollosungen in Tetrahydrofaran stark exothermisch sind; der 2. Virialkoeffizient des osmotischen Druckes A2 wird uberwiegend durch den Enthalpieterm A2,H bestimmt. Der Expansionskoeffizient gehorcht der (α5−α3)-Beziehung mit der Konstante von STOCKMAYER und die h(z)-Funktion der Gleichung von CASASSA. Die Viskositatszahl [η] wird durch die Gleichung von KURATA und YAMAKAWA erfast. Mit den drei Parametern β/M, K0 = r/M und b/M (b = hydrodynamischer Durchmesser) lassen sich A2, α, [η] und der Tragheitsradius r uber einen grosen Molekulargewichts-bereich in guter Ubereinstimmung mit den Meswerten berechnen (vgl. Abb. 3). Light scattering measurements of …
l-Arabinose Conformers Adsorption on Ruthenium Surfaces: A DFT Study
2012
Adsorption of 5 L-arabinose tautomers – one acyclic and four cyclic (α and β, pyranose and furanose) species – on a ruthenium surface was studied as a precursor-process of the, nowadays more and more, industrially important sugar catalytic hydrogenation on metal surfaces in water medium. The study was mostly referred to a 37-atom metal catalyst fragment, even though border-effects on the adsorption processes were also checked employing a 61-atom metal fragment. In order to figure out conformational effects on the title process the tautomer flexibility was, at first, investigated by the genetic-algorithm based code Balloon, considering the conformational spaces of the different aquo tautomer…
Formation of meso-1,2-Bis(dimethylamino)-1,2-diphenylethane by Oxidative C-C Coupling Reaction
2005
The title compound was obtained from the reaction of N,N-dimethylbenzylamine with n-butyl lithium and sulfur in tetrahydrofuran at room temperature. Its molecular structure was investigated by means of single crystal X-ray diffraction and quantum chemical DFT methods. The formation of meso-1,2-bis(dimethylamino)-1,2-diphenylethane is likely to be due to an unusual α-deprotonation of N,N-dimethylbenzylamine, instead of the well known ortho-lithiation, with a subsequent oxidative C-C coupling of the anions. Ab initio calculations of the corresponding α- and o-deprotonated anions of N,N-dimethylbenzylamine showed the former to be more stable than the latter, due to delocalisation of the negati…
Crystal structure of 3-(tri-phenyl-phosphoranyl-idene)-2,5-di-hydro-furan-2,5-dione tetra-hydro-furan monosolvate.
2018
The title pseudo-polymorph of 3-(triphenylphosphoranylidene)-2,5-dihydrofuran-2,5-dione crystallizes with a tetrahydrofuran solvent molecule, viz. C22H17O3P·C4H8O. The succinic anhydride ring is approximately planar (r.m.s. deviation = 0.032 Å). The tetrahydrofuran molecule is disordered over two orientations about a pseudo-twofold axis with refined occupancy ratio 0.718 (4):0.282 (4). In the crystal, C—H...O hydrogen bonds link molecules of the dihydrofuran-2,5-dione derivative into chains parallel to the b axis and arranged into layers stacked along [100] alternating with hydrogen-bonded tetrahydrofuran layers.
Crystal structure, Hirshfeld surface analysis and electrostatic potential study of naturally occurring cassane-type diterpenoid Pulcherrimin C monohy…
2019
Single crystal X-ray diffraction analysis and Hirshfeld surface analysis of the title compound were carried out to analyse quantitatively the intermolecular interactions involved in the crystal packing. The electrostatic potential surface was generated over the Hirshfeld surface to visualize the potential active sites.
Crystal structure and computational study of 3,4-dihydroxy-3-hydroxymethyl-9-methyl-6-methylidene-3a, 4,5,6,6a, 9,9a, 9b-octahydroazuleno[4,5-b]furan…
2015
WOS: 000370762300147
Crystal structure of a rare trigonal bipyramidal titanium(IV) coordination complex: trichlorido(3,3′-di-tert-butyl-2′-hydroxy-5,5′,6,6′-tetramethyl-1…
2017
The title compound, [Ti(C24H33O2)Cl3(C4H8O)], is a rare example of a trigonal–bipyramidal titanium coordination complex with three chloride and two oxygen donor ligands. The asymmetric unit contains two independent molecules having essentially the same conformation. The molecules feature the titanium(IV) metal cation complexed with three chloride ligands, a tetrahydrofuran molecule, and one oxygen atom from the resolved ligand precursor (R)-(+)-5,5′,6,6′-tetramethyl-3,3′-di-t-butyl-1,1′-biphenyl-2,2′-diol, where the remaining phenolic hydrogen atom engages in intermolecular O—H...Cl hydrogen bonding. In one molecule, the THF ligand is disordered over two orientations with refined site occup…
Towards Translational ImmunoPET/MR Imaging of Invasive Pulmonary Aspergillosis: The Humanised Monoclonal Antibody JF5 Detects Aspergillus Lung Infect…
2017
Invasive pulmonary aspergillosis (IPA) is a life-threatening lung disease of hematological malignancy or bone marrow transplant patients caused by the ubiquitous environmental fungus Aspergillus fumigatus. Current diagnostic tests for the disease lack sensitivity as well as specificity, and culture of the fungus from invasive lung biopsy, considered the gold standard for IPA detection, is slow and often not possible in critically ill patients. In a previous study, we reported the development of a novel non-invasive procedure for IPA diagnosis based on antibody-guided positron emission tomography and magnetic resonance imaging (immunoPET/MRI) using a [64Cu] DOTA-labeled mouse monoclonal anti…
CCDC 1817831: Experimental Crystal Structure Determination
2018
Related Article: Ondřej Jurček, Hennie Valkenier, Rakesh Puttreddy, Martin Novák, Hazel A. Sparkes, Radek Marek, Kari Rissanen, Anthony P. Davis|2018|Chem.-Eur.J.|24|8178|doi:10.1002/chem.201800537