Facile Synthesis of 1-Azospiro(5.5)Undecan-2,7-Dione

Abstract

Interest in the 1-azospiro(5.5)undecane ring system has increased dramatically due to the interesting chemical¹ and neurophysiological² properties of the toxins derived from the South American frog Dendrobates histrionicus, which contain this ring system. The principal alkaloid, histrionicotoxin, Ia, has resisted synthetic efforts³ to date, though the octahydro compound Ib has been prepared recently⁴, and there are three reported syntheses^4,5 of the perhydro derivative Ic, which is an inhibitor of the ionic transduction system in synaptic membranes. In addition, several approaches to model compounds and potential synthetic precursors have been reported.⁶