Sökning: "Racemic Resolution"

Visar resultat 1 - 5 av 26 avhandlingar innehållade orden Racemic Resolution.

  1. 1. Lipase catalysed reactions of terpenoids : formation of hemiacetal esters : resolution of cryptone and its transformation to cadinenes

    Författare :Dan Isaksson; Fredrik Almqvist; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; terpenoid; lipase; resolution; hemiacetal; hemiacetal ester; enantioselective; synthesis; cryptone; cadinene; Organic chemistry; Organisk kemi;

    Sammanfattning : During attempted enzyme-catalysed resolution of sterically hindered secondary alcohols, hemiacetals and their esters were unexpectedly detected. Hemiacetal esters are reactive compounds that decompose to alcohol, aldehyde and acid under ordinary work-up conditions i.e. in contact with water, acid, or silica gel. LÄS MER

  3. 2. Absolute Asymmetric Synthesis

    Författare :Anders Lennartson; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; absolute asymmetric synthesis; enantioselective synthesis; chirality; optical resolution; spontaneous resolution; conglomerate; organozinc reagents; organometallic chemistry; coordination chemistry; supramolecular chemistry; intermolecular interactions; optical resolution;

    Sammanfattning : Absolute asymmetric synthesis is the synthesis of optically active products from achiral or racemic precursors only. This has generally been regarded as impossible and is relevant in the discussion of the origins of biomolecular homochirality. LÄS MER

  4. 3. On the separation of enantiomers by direct crystallization

    Författare :Veronica Profir; KTH; []
    Nyckelord :optical resolution; direct crystallization; threonine; mandelic acid; racemic compound; nucleation of metastable conglomerate; in situ concentration measurements; IR spectroscopy; multivariate calibration.;

    Sammanfattning : .... LÄS MER

  5. 4. Synthetic Transformations via Metal- and Enzyme-Catalyzed Dynamic Kinetic Resolution

    Författare :Krisztián Bogár; Jan-Erling Bäckvall; Romas Kazlauskas; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ruthenium; racemization; lipase; dynamic kinetic resolution; secondary alcohol; Candida antarctica lipase B; Organic chemistry; Organisk kemi; Organic Chemistry; organisk kemi;

    Sammanfattning : This thesis deals with the preparation of a new half-sandwich type ruthenium(II)- catalyst for racemization of optically active secondary alcohols and the development of a highly efficient method in combination with lipases such as Candida antarctica lipase B and Pseudomonas cepacia lipase for dynamic kinetic resolution of various functionalized alcohols under mild reaction conditions.It was shown that the RuCl(CO)2(η5-C5Ph5) complex can racemize optically active aliphatic and aromatic secondary alcohols at room temperature in rather short times. LÄS MER

  7. 5. Enzyme- and Transition Metal-Catalyzed Asymmetric Transformations : Application of Enzymatic (D)KR in Enantioselective Synthesis

    Författare :Richard Lihammar; Jan-Erling Bäckvall; Wolfgang Kroutil; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Dynamic Kinetic Resolution; Kinetic Resolution; Enzyme Catalysis; Asymmetric Synthesis; organisk kemi; Organic Chemistry;

    Sammanfattning : Dynamic kinetic resolution (DKR) is a powerful method for obtaining compounds with high optical purity. The process relies on the combination of a kinetic resolution with an in situ racemization. LÄS MER