Search for dissertations about: "epimerization"

Showing result 1 - 5 of 20 swedish dissertations containing the word epimerization.

  2. 1. Efficient carbohydrate synthesis by controlled inversion strategies

    Author : Hai Dong; Olof Ramström; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Carbohydrate Chemistry; Carbohydrate Protection; Epimerization; Inversion; Dynamic; Regioselective Control; Neighboring Group Participation; Organic chemistry; Organisk kemi;

    Abstract : The Lattrell-Dax method of nitrite-mediated substitution of carbohydrate triflates is an efficient method to generate structures of inverse configuration. In this study it has been demonstrated that a neighboring equatorial ester group plays a highly important role in this carbohydrate epimerization reaction, inducing the formation of inversion compounds in good yields. READ MORE

  4. 2. Progesterone metabolites : learning, tolerance, antagonism & metabolism

    Author : Charlotte Öfverman; Inga-Maj Johansson; Torbjörn Bäckström; Esa Korpi; Umeå universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; allopregnanolone; isoallopregnanolone; THDOC; learning; tolerance; antagonism; inhibition; patch clamp; Morris water maze; metabolism; epimerization; Obstetrics and gynaecology; Obstetrik och gynekologi; obstetrik och gynekologi; Obstetrics and Gynaecology;

    Abstract : Progesterone metabolites as allopregnanolone, isoallopregnanolone and tetrahydrodeoxy-corticosterone (THDOC) are increased in the luteal phase of the menstrual cycle, throughout pregnancy and during stress. Allopregnanolone and THDOC are neurosteroids with 3α-hydroxy, 5α-configurations and positive modulating effect on the GABAA receptor. READ MORE

  5. 3. Ruthenium-catalyzed redox reactions and lipase-catalyzed asymmetric transformations of alcohols

    Author : Michaela Edin; Jan-E. Bäckvall; Manfred T. Reetz; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; ruthenium; lipase; catalysis; alcohols; diols; Chemistry; Kemi;

    Abstract : The major part of this thesis describes the synthesis of enantiopure alcohols and diols by combining ruthenium-catalyzed redox reactions that lead to racemization or epimerization and lipase-catalyzed asymmetric trans-formations in one-pot.A mechanistic study of the unexpected facile formation of meso-diacetate products found in enzyme-catalyzed acetylations of alkanediols with Candida antarctica lipase B (CALB) was first performed. READ MORE

  6. 4. Synthesis and asymmetric transformations of diols by enzyme- and ruthenium catalysis

    Author : Karin Leijondahl; Jan-Erling Bäckvall; Kurt Faber; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; dynamic kinetic asymmetric transformation; diols; enzymatic transformations; catalysis; ruthenium; transfer hydrogenation; Organic chemistry; Organisk kemi; Organic Chemistry; organisk kemi;

    Abstract : The major part of this thesis describes the synthesis of aliphatic secondary diols and the development of lipase- and ruthenium-catalyzed asymmetric transformations of these diols. Several acyclic 1,4-diols and 1,5-diols were synthesized, and by combining a lipase-catalyzed asymmetric transformation with a ruthenium-catalyzed epimerization, enantiomerically- and diastereomerically enriched diacetates were obtained. READ MORE

  7. 5. Aspects on dermatan sulfate metabolism

    Author : Erik Eklund; Matrixbiologi; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Klinisk biologi; Clinical biology; iduronic acid; galactosaminoglycan; Dermatan sulfate; biosynthesis;

    Abstract : The functions of proteoglycans often depend on the fine structure of the covalently attached glycosaminoglycan (GAG) side-chains. The process leading to the mature GAG is complex and involves a multitude of different enzymatic steps. READ MORE