Sökning: "ring-contraction"

Hittade 3 avhandlingar innehållade ordet ring-contraction.

  1. 1. Synthesis and Rearrangement of Epoxy Sugars

    Författare :Fritiof Pontén; Centrum för analys och syntes; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Organisk kemi; Organic chemistry; crown ether; silica; Intramoleculaf Diels-Alder reaction; radical allylation; allyl sulfone; sugar epoxide; allyl sulfide; ring-contraction; C-glycoside; a; IMDAF; b-unsaturated aldehyde;

    Sammanfattning : Ring-Contraction of sugar-derived epoxy alcohols, functionalised in position 1 and 6, by treatment with lithium bromide and N, N, N', N'-tetramethylurea in refluxing toluene gave enantiomerically pure a,b-unsaturated aldehydes of furanosides. O-Glycosidic epoxy alcohols gave only one, easily purified, aldehyde in approximately 30-60% yield depending on the substitution pattern. LÄS MER

  3. 2. Total synthesis of enantiomerically pure natural products via chiral unsaturated aldehydes formed by ring-contraction of sugar epoxides

    Författare :Nicola Rehnberg; Centrum för analys och syntes; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : .... LÄS MER

  4. 3. Synthesis of heterocycles from anthranilic acid and its derivatives

    Författare :Per Wiklund; Jan Bergman; Norbert de Kimpe; Södertörns högskola; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Anthranilic acid; synthesis; heterocycles; benzodiazepines; HNO nitrosyl ;

    Sammanfattning : Anthranilic acid (2-aminobenzoic acid, Aa) is the biochemical precursor to the amino acid tryptophan, as well as a catabolic product of tryptophan in animals. It is also integrated into many alkaloids isolated from plants. Aa is produced industrially for production of dyestuffs and pharmaceuticals. LÄS MER