Biologisch aktive Heterozyklen

Buchgraber, Philipp

Biologisch aktive Heterozyklen

dc.contributor.advisor	Fürstner, Alois
dc.contributor.author	Buchgraber, Philipp
dc.contributor.referee	Hiersemann, Martin
dc.date.accepted	2008-06-17
dc.date.accessioned	2008-09-02T09:59:44Z
dc.date.available	2008-09-02T09:59:44Z
dc.date.issued	2008-09-02T09:59:44Z
dc.description.abstract	Low-valent titanium reagents, [Ti], have proven to be useful for heterocycle synthesis. In this thesis a [Ti] induced cascade reaction for the construction of biologically interesting [2,3]- annulated carbazole derivatives from polycarbonyl compounds is described. Furthermore, the reaction of 2,2´-biaryl ketoesters to form 9-phenanthrenol derivatives is reported. This transformation, however, is limited to aryl ketones to ensure high yields. Besides 2,2´-biaryl ketoesters, ketoacids, -amides, -cyanides and a -phthalimide reacted readily to the desired phenanthrene derivatives. Only an acid fluoride derivative reacted to afford a phenanthrenol rather than the desired 9-fluorophenanthrene. The second part focuses on the total synthesis of berkelic acid, a tetracyclic spiroketal natural product from an antropogenic source. A convergent synthesis furnished the tetracyclic core of berkelic acid via a 1,4-addition / thermodynamic acetalization cascade, thereby demonstrating the thermodynamic lability of this spiroketal. Careful analysis of NMR data, and the unexpected acid lability, led to the preparation of a diastereomer of the proposed structure. This stable diastereomer confirms the revision of relative configuration of the tetracyclic core of berkelic acid.	en
dc.identifier.uri	http://hdl.handle.net/2003/25787
dc.identifier.uri	http://dx.doi.org/10.17877/DE290R-868
dc.identifier.urn	urn:nbn:de:hbz:290-2003/25787-3
dc.language.iso	de	de
dc.subject	Heterocyclen	de
dc.subject	Niedervalentes Titan	de
dc.subject	Berkelic Acid	de
dc.subject	Berkelsäure	de
dc.subject	Naturstoffsynthese	de
dc.subject	Strukturaufklärung	de
dc.subject.ddc	540
dc.title	Biologisch aktive Heterozyklen	de
dc.type	Text	de
dc.type.publicationtype	doctoralThesis	de
dcterms.accessRights	open access