Stereoselective construction of the azabicyclic core applicable to the biologically important polyguanidinium alkaloids batzelladine A and D using a free radical cyclization

The intramolecular addition of the free radical derived from the alkyl bromide 13 provides an expeditious and stereoselective approach to the azabicyclic core 14, which is applicable to the biologically important polyguanidinium alkaloids batzelladine A (1) and D (2).