Graduate / 0485

This Thesis describes some [3,3] and [2,3] -sigmatropic rearrangements that can occur in a variety of polyfluoroaromatic and -heteroaromatic compounds. The presence of fluorine on the aromatic moiety precludes the normal rearomatization process. The work is conveniently divided into two parts. Part A concerns the preparation and thermal (Claisen) rearrangement of derivatives of allyl 5-fluoropyrimidin-4-yl ether. These rearrange upon thermolysis to give isomers in which the terminus for the migration of the allyl group is N-3, provided that there is no preceding reaction which localises a double- bond between C-4 and C-5 - in which case C-5 is the migration terminus. Hydrolysis of some of the N-allyl derivatives results in the formation of some new derivatives of 5-fluorouracil. Part B describes the reactions that occur when polyfluor - inated monocyclic, polycyclic and heterocyclic ring systems are treated with dimethylsulphoxide activated by dicyclohexycarbodi-imide or by trifluoroacetic anhydride. Fluorinated phenolic type compounds give products which are the result of a [2,3] sigmatropic rearrangement of the derived sulphoniumylide. Fluorinated anilines and thiophenols behave differently. Dearomatization occurs under very mild conditions. A number of reactions of the fluorinated cyclohexa-2,4-dienone products are described. The preparation and attempted rearrangement of 2,3,4,5,6- pentafluorobenzylmethylsulphoxide is also discussed.

No description available.

Methyl 4-trimethylsilyl-3-dialkylaminocrotonate is synthesized by the silylation of methyl 3-dialkylaminocrotonate. It reacts with carbonyl electrophiles at its (gamma)-position. The unusual regiochemistry of this reaction is studied and rationalized. It reacts with enamines derived from acyclic ketones or cycloketones of large ring size (of 12 and 15 membered rings) to give aromatic compounds in a 3C + 3C combination and with enamines derived from cycloketones of 5-8 membered rings to give aromatic compounds in a 4C + 2C combination. The mechanism of this cycloaromatization reaction is investigated. / meta-Cyclophanes with a morpholino substituent are synthesized by the above cycloaromatization reaction. These meta-cyclophanes possess planar chirality and are successfully resolved. / A number of metacyclophanes with alkyl substituents at the intraannular position are synthesized. Depending on the ring size and the steric size of the alkyl group, some of them are also resolved. The rotation process of meta-cyclophane is studied through their temperature dependent ('1)H NMR.

Thesis (Ph. D.)--Virginia Polytechnic Institute, 1963. / Vita. Abstract. Includes bibliographical references (leaves 84-85). Also available via the Internet.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1989. / Vita. Abstract. Includes bibliographical references (leaves 69-71). Also available via the Internet.

Thesis (Ph.D.)---University of Adelaide, 1955. / Typewritten copy.

Thesis (Ph. D.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed Dec. 27, 2007). Includes bibliographical references.

Thesis (Ph. D.)--University of Oregon, 2008. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 265-281). Also available online in Scholars' Bank; and in ProQuest, free to University of Oregon users.

Thesis (M.S.)--University of North Texas, Dec., 2007. / Title from title page display. Includes bibliographical references.