Sökning: "Convergent synthesis"

Visar resultat 1 - 5 av 20 avhandlingar innehållade orden Convergent synthesis.

  1. 1. Methods for Asymmetric Olefination Reactions; Development and Application to Natural Product Synthesis

    Författare :Daniel Strand; Tobias Rein; Viresh Rawal; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Antitumor agents; Asymmetric Horner-Wadsworth-Emmons; Desymmetrization; Metal-catalyzed olefination; Mucocin; Palladium-catalyzed allylic substitution; Parallel kinetic resolution; Pyranicin; Pyragonicin; Rhenium; Stereoconvergent synthesis; Stereodivergent synthesis; Stereoselective synthesis; Tetrahydropyran; Wittig reaction; Organic chemistry; Organisk kemi;

    Sammanfattning : This thesis deals with the development and application of methods for asymmetric olefinations, in particular Horner-Wadsworth-Emmons (HWE) reactions, in the synthesis of certain natural products. Relying on asymmetric HWE reactions to access key building blocks, two natu-ral products, pyranicin and pyragonicin, were synthesized from common late intermediates. LÄS MER

  3. 2. Enantio- and Regioselective Iridium-Catalyzed Hydrogenation of Olefins : From Development to Total Synthesis

    Författare :Cristiana Margarita; Pher Andersson; Xavier Verdaguer; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Asymmetric hydrogenation; Iridium; Regioselectivity; Kinetic resolution; Total synthesis; organisk kemi; Organic Chemistry;

    Sammanfattning : The work presented in this thesis concerns the iridium-catalyzed asymmetric hydrogenation of cyclic olefins and allylic alcohols for the preparation of useful chiral intermediates with various substitution patterns. The strategy provides stereocontrol for both non-functionalized as well as functionalized substrates and aims to be implemented in the stereoselective preparation of chiral building blocks having more than one stereocenter. LÄS MER

  4. 3. Natural products from nonracemie building blocks : synthesis of pine sawfly pheromones

    Författare :Michael Larsson; Torbjörn Norin; Gunnar Westman; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Organic chemistry; Total synthesis; diastereoselective addition; dimethylzinc; Lewis acid; alkyllithium; Organisk kemi; Organic chemistry; Organisk kemi;

    Sammanfattning : This thesis describes a number of synthetic approaches for obtaining chiral, enantiomerically pure natural products, in particular some semiochemicals. This has been accomplished by using various strategies; by starting from compounds from the chiral pool, by using chiral auxiliaries, via enzymatic resolutions or by chemical asymmetric synthesis. LÄS MER

  5. 4. Integrated Frequency Synthesis for Convergent Wireless Solutions

    Författare :Jad G. Atallah; Mohammed Ismail Elnaggar; Erik Bruun; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wireless; transceiver; Bluetooth; DECT; GSM; 3G; LTE; WLAN; WiMAX; multi-standard; vertical handover; Sniffer; frequency synthesizer; phase-locked loop; PLL; sigma-delta; calibration; Electronics; Elektronik;

    Sammanfattning : Wireless transceivers combining several standards in one unit are of key importance. In order to reach the ultimate goal of maximizing the performance-to-cost ratio of such modules, a careful study of the target application, the architecture, and the frequency planning is strongly required. LÄS MER

  7. 5. New synthetic routes to azaspiro alkaloids : Applications to the synthesis perhydrohistrionicotoxin

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

    Sammanfattning : Perhydrohistrionicotoxin, 1, is related to a family of alkaloids which display pharmacologically interesting properties. The thesis deals with development of new methods for the chemical synthesis of such alkaloids, and is divided into three parts according to the different approaches. LÄS MER