| Summary: | Chapter One describes several natural products derived from the amino acid tryptophan including the structures of the new natural products hyrtioseragamine A and B and tintamine.
Chapter Two describes the work towards hyrtioseragamine A and B. It was intended that the unknown furo[2,3-b]pyrazine-2(1H)-one core would be synthesised from a 1,4-dicarbonyl and this has been synthesised from the amino acid ornithine and the tryptophan derivative kynurenine. Cyclisation of this material to give the 2,3-amino-furan was unsuccessful and thus a number of model systems were synthesised to examine the barrier to furan formation. These models suggest formation of a furan with nitrogen at its 2- and 3-positions was not possible by this route, and further attempts to install a nitrogen to a 2-amino-furan also proved unsuccessful.
Chapter Three describes work on the synthesis of the marine natural product tintamine. This novel compound contains a unique tropo-1,2-dihydro-3,6-phenanthroline core and our synthesis was based on biomimetic principles. A FriedlÓ“nder reaction allowed successful formation of the quinoline and the attached seven-membered ring was further functionalised to a tropolone. Formation of the dihydro-phenanthroline was successful; it was also possible to separately functionalise the tropolone-quinoline with the sulfur side chain present in tintamine. Unfortunately several of the key intermediates of this route proved unstable, and at this point a final deprotection to form the natural product has not been successful.
Chapter Four contains the synthetic details for the preparation of the novel compounds described in Chapters Two and Three.
|
|---|