Sökning: "Epimerization"
Visar resultat 1 - 5 av 20 avhandlingar innehållade ordet Epimerization.
1. Efficient carbohydrate synthesis by controlled inversion strategies
Sammanfattning : 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. LÄS MER
2. Progesterone metabolites : learning, tolerance, antagonism & metabolism
Sammanfattning : 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. LÄS MER
3. Ruthenium-catalyzed redox reactions and lipase-catalyzed asymmetric transformations of alcohols
Sammanfattning : 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. LÄS MER
4. Synthesis and asymmetric transformations of diols by enzyme- and ruthenium catalysis
Sammanfattning : 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. LÄS MER
5. Aspects on dermatan sulfate metabolism
Sammanfattning : 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. LÄS MER