Synthetic Studies Toward Complex Polycyclic Natural Products

[摘要] The first chapter of this dissertation describes the use of an intramolecular Staudinger/aza-Wittig reaction in the synthesis of 1,2,5,6-tetrahydro-1,2,4-triazines, a structural motif of the natural product noelaquinone. The DEF ring system of noelaquinone was prepared in 13 steps and 2% overall yield with key steps featuring a Cu(I)-catalyzed C-arylation and the controlled acidic hydrolysis of the PMB protective group.The second chapter describes the investigation of reactions between methyl 3-oxo-2-oxabicyclo[2.2.0]hexane-6-carboxylate and an indolo-indoline dimer in the presence of BF3·OEt2. Two tricyclic-fused heterocyclic products and a diene carboxylic acid have been obtained through a ring opening process, a retro-[2+2] cycloaddition, and a conjugate addition from the indole fragment.The third chapter describes progress toward the total synthesis of haouamine A. Several routes to the marine alkaloid have been attempted. The challenges associated with the late stage lactam reduction, epoxidation, and aromatization strategy to prepare the necessary tetrahydropyridine and aza-cyclophane moieties are discussed.

[发布机构] the University of Pittsburgh