Search for dissertations about: "intramolecular alkylation"

Showing result 1 - 5 of 6 swedish dissertations containing the words intramolecular alkylation.

2. 1. Enzymes as catalysts in synthesis of enantiomerically pure building blocks : secondary alcohols bearing two vicinal stereocenters

   Author : Rong Liu; Hans-Erik Högberg; Torbjörn Norin; Thorleif Anthonsen; KTH; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; enzyme; kinetic resolution; enantioselectivity; lipase; diastereoselectivity; epimerisation; metal-catalysed transformation; intramolecular alkylation.; Chemistry; Kemi;

   Abstract : Enzymes as tools in organic synthesis have provided enormous advantages. This thesis deals with the applications of enzymes in the kinetic resolutions of racemic compounds. The stereochemistry of chiral compounds and the kinetics of α/β hydrolase lipases are presented. READ MORE

4. 2. Ruthenium complexes and substituted polypyridines in photophysical and electron transfer studies

   Author : Thomas Norrby; KTH; []
   Keywords : ;

   Abstract : Organic molecules acting as electron acceptors and ligandsfor metal complexes were synthesized. N-alkylation of4,4'-bipyridine and nicotinamide yielded electron transport andacceptor molecules. By regioselective functionalization of2,2'-bipyridine (bpy), several novel ligand molecules wereobtained. READ MORE

5. 3. Mechanism Studies of Catalytic RNA, and RNA and DNA Model Compounds

   Author : Ethel Pettersson; Eric Westhof; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Organic Chemistry; organisk kemi;

   Abstract : This thesis describes mechanism studies of transesterifications of phosphate esters. The aim of the studies concerns two fields. First, the catalytic mechanism that group I introns use in self-splicing. The focus was on metal ion coordinating groups at the catalytic site. READ MORE

6. 4. Aromatic Allylation via Diazotization; Application in synthesis of heterocyclic compounds

   Author : Fredrik Ek; Centrum för analys och syntes; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Bengamide analogue.; parallel synthesis; trimethylsilyl azide; cycloaddition; imidazole; fused tetrazole derivatives; iodocyclization; benzazepine; tert-butyl nitrite; allylic bromide; aromatic allylation; diazotization; Organic chemistry; Organisk kemi;

   Abstract : A new method for allylation of aromatic systems has been developed. A number of arylamines were converted via diazotization to the corresponding allylaromatic compounds using tert-butyl nitrite and an excess of allylic bromides with complete regioselectivity. Electron-withdrawing groups, in the aromatic moiety, were necessary to obtain good yields. READ MORE

7. 5. Synthesis and Rearrangement of Epoxy Sugars

   Author : Fritiof Pontén; Centrum för analys och syntes; []
   Keywords : 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;

   Abstract : 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. READ MORE