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Synthesis of diazatricyclic core of Madangamines from cis-perhydroisoquinolines.

Research paper by Josefina J Quirante, Laura L Paloma, Faïza F Diaba, Xavier X Vila, Josep J Bonjoch

Indexed on: 22 Dec '07Published on: 22 Dec '07Published in: Journal of Organic Chemistry



Abstract

Synthesis of the tricyclic core of madangamine alkaloids has been achieved in a 10-step sequence starting from a 4-(aminomethyl)anisole derivative. A Birch reduction and acylation with cyanoacetic acid followed by an intramolecular Michael process renders a polyfunctionalized cis-perhydroisoquinoline. A diastereoselective allylation and reduction of amide, nitrile, and ketone groups leads to a bicyclic alcohol, which undergoes aminocyclization through the nosyl derivative to the diazatricyclic ring.