Sökning: "stereochemistry"

Visar resultat 16 - 20 av 44 avhandlingar innehållade ordet stereochemistry.

1. 16. Secondary plant metabolites as defence against herbivores and oxidative stress : Synthesis, isolation and biological evaluation

   Författare :Katharina Bratt; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemistry; Kemi; Chemistry; Kemi; organisk kemi; Organic Chemistry;

   Sammanfattning : In this thesis the isolation, synthesis and biological evaluation of natural defense compounds against herbivores or oxidative stress is discussed.The first part concerns the metabolites of platyphylloside ((5S)-5-hydroxy-1,7-bis-(4-hydroxyphenyl)-3-heptanone-5-O-β-D-glucopyranoside), a phenolic glucoside found in birch (Betula pendula) that possess digestibility inhibiting activity in herbivores. LÄS MER

3. 17. Ruthenium(II) Polypyridyl Complexes : Applications in Artificial Photosynthesis

   Författare :Olof Johansson; Licheng Sun; Björn Åkermark; Michael D Ward; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Organisk kemi; Chemistry; Kemi;

   Sammanfattning : Molecular mimics of PS II, which consist of a photosensitizer linked to electron acceptors/donors, are attractive candidates for the conversion of solar energy into chemical energy. Several different classes of sensitizers have been studied and among these, ruthenium(II) polypyridyl complexes continue to attract major attention. LÄS MER

4. 18. Design and synthesis of HIV-1 protease inhibitors

   Författare :Mathias Alterman; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Pharmaceutical chemistry; HIV-1; Protease; Inhibitors; Farmaceutisk kemi; Pharmaceutical chemistry; Farmaceutisk kemi; Organic Pharmaceutical Chemistry; organisk farmaceutisk kemi;

   Sammanfattning : Human Immunodeficiency Virus (HIV) is the causative agent of Acquired Immune Deficiency Syndrome (AIDS). The C2-symmetric HIV-1 protease is one of the prime targets for chemotherapy in the treatment of the HIV infection. Inhibition of HIV-1 protease leads to immature and non-infectious viral particles. LÄS MER

5. 19. Impact of Secondary Interactions in Asymmetric Catalysis

   Författare :Anders Frölander; Christina Moberg; Gerard van Koten; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; asymmetric catalysis; secondary interaction; hydrogen bond; chiral ligand; allylic alkylation; hydrosilylation; cyanation; pymox; box; PHOX; pybox; palladium; iridium; rhodium; Lewis acid; Lewis base; Organic chemistry; Organisk kemi;

   Sammanfattning : This thesis deals with secondary interactions in asymmetric catalysis and their impact on the outcome of catalytic reactions. The first part revolves around the metal-catalyzed asymmetric allylic alkylation reaction and how interactions within the catalyst affect the stereochemistry. LÄS MER

7. 20. 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