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Showing 1 to 20 of 57 for “"diastereomer"”.

  1. Rhodium-katalysierte, asymmetrische Synthese: Ligandendesign und Methodik

    Stemmler, René T.Mainz2007

    … or the Walphos family furnished the exo-diastereomer predominantly and with up to 82% ee. In contrast, the use of monodentate ligands such as the phosphoramidite MonoPhos™ led diastereoselectively to the endo-diastereomer with up to 54% ee. Initial experiments with bidentate …

    aachen Repository record

  2. Understanding the Solid State, Solubility and Dissolution Behavior of Cefuroxime Axetil Diastereomers in Interactive Mixture Formulations

    Dalal, Namita2017

    … present in commercial products as a mixture of diastereomers, which commonly form eutectic mixtures. A phase diagram was constructed utilizing differential scanning calorimetry. It was observed that the diastereomers formed a eutectic mixture with a composition of 75% isomer B and a melting …

    duquesne Repository record

  3. Stereochemical Effect of RAFT Agents on Kinetics of Reversible Deactivation Radical Polymerization

    Lin, ShiyangUNSW, Sydney2020

    … chains. In this thesis, two ideal models (diastereomeric macro-RAFT agents with different chemical structures and two inherent diastereomers for each) were designed and prepared by single unit monomer insertion (SUMI) technology to examine their stereochemical effect on kinetics of RDRP. In …

    unsw Repository record

  4. Investigation of ligand misdirection using the kinetic element effect and the kinetic enthalpy effect.

    Alguindigue, Susan Stanislav.2000

    … and [(eta6-C6H6)Ru(dabp)(Cl)]+. Only one diastereomer was observed for [Ru(bipy)2(dabp)] 2+ in the 1H NMR spectrum. Exchange was observed and measured for the ruthenium and osmium complexes of [(eta6-C 6H6)M(dabp)(Cl)]+.

    oklahoma-thes Repository record

  5. The enantioselective synthesis of C₁₈-sphingosines

    Nugent, Thomas C.Virginia Tech1995

    … via the selective preparation of the appropriate diastereomer of azido alcohol (118), were C-4 and C-5 correspond to C-3 and C-2 of the sphingosine skeleton, respectively (Scheme 1).

    vt Repository record

  6. The Synthesis-Enabled Stereochemical Elucidation of the Marine Natural Products Hemicalide and Phormidolide A

    Lam, Nelson Yuen SumUniversity of Cambridge2019

    … C16-C25 and C35-C46 fragments to a single diastereomer with reasonable confidence. However, the relative configuration between fragments and the absolute stereochemistry remains unknown. Part II describes the synthesis of the C16-C28 dihydroxylactone fragment, which was used to successfully …

    cambridge Repository record

  7. Total Syntheses of 1,2,4-Thiadiazole Natural Products

    Davison, EmmaResearchSpace@Auckland2018

    … to form natural products 24a and 24b, along with diastereomer 144a/b. The result of the biomimetic thio-Diels-Alder reaction was supported by DFT analysis and corroborated the postulate made in the original report that the C-2' alcohol of (±)-31 is too distant from the forming spirocentre to exert …

    auckland-ms Repository record

  8. I. Catalyst development in asymmetric phase transfer catalysis employing QSAR methods II. Computational investigations on the stereochemical course of the addition of allylsilanes to aldehydes

    Wolf, LawrenceUniversity of Illinois at Urbana-Champaign2013

    … manifold. The selectivity for the syn diastereomer in the electrophilic activation manifolds is accounted for by increased electrostatic and orbital interactions for a particular synclinal transition state at the expense of increased steric interactions relative to antiperiplanar …

    uiuc Repository record

  9. Asymmetrische Totalsynthese von 16(S)-Iloprost und 3-Oxa-16(S)-Iloprost mittels der Azoen-Strategie

    Kramp, Guido JohannesPublikationsserver der RWTH Aachen University2005

    … Ventavis registrated iloprost (1:1 mixture of diastereomers at C16) serves as a drug against ischemic heart disease, peripheral vascular disease and primary pulmonary hypertension. The 16S-diastereomer is 5 to 20 times more potent than the 16R-diastereomer in inhibiting collagen-induced …

    aachen Repository record

  10. Neurotransmitter and Neuromodulator Analysis Using Capillary Electrophoresis With Laser -Induced Fluorescence Detection

    Miao, HaiUniversity of Illinois at Urbana-Champaign2015

    … been developed and the D-form dominates in one diastereomer pair. Lastly, in preliminary studies, the release of L-Glu versus acetylcholine from specific regions of the brain of freely moving rats appears dependent on stimulation parameters, causing differential regulation of the circadian …

    uiuc Repository record

  11. Studies Towards the Total Synthesis of Patellazole B

    Phillips, AndrewUniversity of Cambridge2017

    … comparison studies. The synthesis of all eight diastereomers of this macrocycle should aid determination of the four unknown stereocentres. Chapter 2 describes the synthesis of the C1–C12 fragment, focusing on the configuring of the C5 methyl stereocentre and the construction of the C7-C10 …

    cambridge Repository record

  12. Investigations into cyclopropanation and ethylene polymerization via salicylaldiminato copper (II) complexes

    Boyd, Ramon CornellUniversity of Saskatchewan2007

    … the ethyl trans-2-phenylcyclopropanecarboxylate diastereomer. Steric bulk poorly influences trans:cis ratios. Salicylaldiminine ligands do not posses the correct symmetry to affect diastereoselectivity. The SAL ligand belongs to the Cs point group in the solid state. Other ligand motifs are more …

    sask Repository record

  13. Advancements in the diastereoselective synthesis of acyl pyrrolidines via the tandem aza-Cope—Mannich cyclization pathway

    St. Germaine, Danielle2018

    … oxazolidine starting material as a mixture of diastereomers to produce one pyrrolidine diastereomer. Both ethyland substituted phenyl-oxazolidines were successfully rearranged. This work is the first example of a truly catalytic aza-Cope—Mannich reaction and provides the first examples of …

    emich Repository record

  14. Applications of Hypervalent Iodine Reagents: From Enantioselective Copper-Catalysed Arylation-Semipinacol Cascade to Methionine Functionalisation for Peptide Macrocyclisation

    Lukamto, Daniel HartoyoUniversity of Cambridge2018

    … and enantioselectivities, and often as a single diastereomer. These are in turn useful functional handles for transformations into other moieties, including further rearrangements via Baeyer-Villiger oxidation. In the second part of this thesis, a two-step process for the macrocyclisation of …

    cambridge Repository record

  15. Subcomponent self-assembly of cages and mechanically interlocked molecules

    Speakman, NatashaUniversity of Cambridge2025

    … cage, which exists as a mixture of diastereomers at room temperature. Cooling the sample to 253 K results in the selective formation of the S₄-symmetric CuI₆L₄ diastereomer. Changing the solvent from MeCN to DMSO gives a mixture of the S₄-symmetric and T-symmetric diastereomers at …

    cambridge Repository record

  16. The asymmetric synthesis of (2S,3R)-capreomycidine and the total synthesis of capreomycin IB

    DeMong, Duane Eugene, author, Williams, Robert M., advisorColorado State University. Libraries2003

    … trialkyl orthoformate to provide a single diastereomer of the glycinate adduct. Hydrogenolysis provides the optically pure acetal of α-formylglycine. Finally, the total synthesis of capreomyc in IB is described. The synthesis features the incorporation of the previously prepared …

    colostate Repository record

  17. Donor-Acceptor Cyclobutanes and Their Application for Heterocycle Synthesis and Progress Towards Biselide A

    Machin, BenjaminThe University of Western Ontario2013

    … A. Key reactions for the formation of a single diastereomer of an advanced stage intermediate included: Evans’ asymmetric aldol and a Prasad reduction to form a 1,3-syn diol exclusively which cyclized with Co(nmp)2 in high yield (93%). A tethering strategy will be used for the formation of the …

    uwo Repository record

  18. Diastereoselective acylation of trans-2-substituted-cyclohexanols and glycosidase inhibition studies

    Samoshin, Andrey V.2018

    … i.e. produces mixtures of unequal amounts of diastereomers. We found for the first time that addition of pyridine or diisopropylethylamine accelerates the acylation, and unexpectedly for some substituents (RX) may completely invert its diastereoselectivity. These observations have been …

    u-pacific Repository record

  19. Theoretical and computational modeling of peptide-lipid bilayer interaction studied by dynamic force spectroscopy

    Utjesanovic, MilicaUniversity of Missouri--Columbia2019

    … energetics of the peptide melittin (MWT) and its diastereomer (MD4) interacting with POPC and POPG lipid bilayers. The obtained results provide further insight into the role of secondary structure in peptide-lipid bilayer interactions.

    missouri Repository record

  20. Applications of 2,3-Diketoesters in Organic Synthesis and Stereoselective Transformations

    Truong, Phong Minh2014

    … catalysis produces the corresponding 1,3-syn diastereomer. The first enantioselective transformation of 2,3-diketoesters was demonstrated in carbonyl-ene reactions catalyzed by [Cu((S,S)-tert-Bu-box)](SbF6)2 generating chiral α-functionalized-α-hydroxy-β-ketoesters in up to 94% yield and 97% …

    maryland Repository record

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