Abstract EN:

In the first part of this work, a stereoselective synthesis of enantiopur multiprotected Kanosamine was achieved. Starting from readily available α-aminodienone (tricarbonyl)iron complex, an aldol reaction is the key reaction. Reduction of the formed ketol, protection of the hydroxyl groups, decomplexation followed by reductive ozonolysis afforded the required multiprotected Kanosamine. In the second part, a new route to hydroazulenic systems was investigated. Aldolisation reaction, the key step, afforded the corresponding ketol with total diastereoselectivity. After the synthesis of the corresponding 1,4-diketone, methanolysis of the latter generated a tricyclic alcohol that is close to the target molecule. Grob Fragmentation should enable the access to enantiopure hydroazulens. In the last part, polyfunctionnalized 2-methyltetralone led to a fused tricyclic allenoate by an intramolecular alkynylogous Mukaiyama aldol type reaction. After five steps, allenoate afforded to Hamigeran B.