Studies on synthesis of octahydropyrido [3,2-c] carbazole skeleton

Indole alkaloids, which constitute a significant portion of alkaloids, attract the attention of researchers due to biological properties and chemical structures. Aspidosperma alkaloids, which are examples of indole alkaloids, allow synthesis of different products because of their pentacyclic structure. Aspidosperma alkaloids and their dimers have got many biological effects, especially antitumor effects. These effects have supported scientific studies. Interest of these molecules still continues for human health medicine, pharmacology and biomolecular studies.Synthesis of octahydropyrido [3,2-c] carbazole skeleton, which is essential for aspidosperma alkaloids, is an important step in many studies and a large part of these studies is for the synthesis of this main skeleton. These studies examined that the reaction steps were quite long and synthesis process was required difficult conditions. In this thesis, synthesis of new tetrahydrocarbazol-4-one derivatives related to obtain octahydropyrido [3,2-c] carbazole skeleton in fewer steps was carried out. Using tetrahydrocarbazol-4-one-3-carboxylate and tetrahydrocarbazol-1-one-2-carboxylate compounds, new tetrahydrocarbazole derivatives containing a spirolactam ring were synthesized. Additionally, double bond in the third position of tetrahydrocarbazol-4-one also obtained and an alpha-beta unsaturated carbonyl compound was synthesized. Participation of the appropriate groups to this alpha-beta unsaturated carbonyl compound via Michael addition have been studied. Finally, reduction of N-tosyl-4-oxo tetrahydrocarbazol-3-propannitrile, which was synthesized in six steps previously, was carried out and resulted in formation of the fourth ring.