Organska kemija (Slovene)

The studies involve one-step tandem cyclizations leading to '5+5' and '5+6' bi-cyc-lic heterocycles. The applications of ?- and ?- amino acids for the preparation of imidazo/1,2-a/pyrimidinyl sugars are planned. Further activities include trans-for-mat-ions of ?-amino acids towards imidazo/1,2-a/pyridines, imidazo/1,2-a/quino-lines and pyrido/1,2-a/pyrazines. We also investigate new approaches to spiro-oxazo-line systems that employ 1,2-diamino- aromatic or heteroaromatic compounds and 2-benzoyl-amino-3-chloropropenoic acid. Another studies deal with the transformation of pyran-2-on building block into didehydroamino acid derivatives. Cycloadditions, sub-stitutions and other reactions under high pressure (10?15 kbar) are also a part of our endeavours. Furthermore, applications of diazenecarboxamides for the selective oxidations of thiols to disulfides and selenols to diselenides are studied. The same diazene-carboxa-mides are also subjected to cyclic voltammetry to get more information concerning their cathodic potentials. Another aspect of diazenecarboxamides involves their abilities as the reagents for aromatic electrophilic aminations, which results in regioselective processes regarding both partners. Depending on the reactivity of an aromatic substrate one can expect either inter- or intramolecular reaction. New compounds which can serve as fluorescent probes are also studied. The research is directed to new derivatives that can easily be employed for the introduction of radioactive fluorine atom (18F). The 18F labelled species are applied in collaboration with our colleagues from UCLA for the in vitro and in vivo studies of the changes of the central nerve system connected with the Alzheimer disease. Furthermore, new deriva--tives containing tropane skeleton are prepared in order to serve in Positron Emission Tomo-graphy (PET) to follow the changes in dopamine system (the Parkinson disease, abuse of drugs, etc.).