Cage adamanzanes are tricyclic tetraamines with four bridgehead tertiary nitrogens linked by carbon chains. In pioneering work, Springborg¹ synthesized a number of adamanzanes, all of which were inside-protonated. We wish to report several new members of this this class of compounds. Adamanzanes 3 and 4 were successfully synthesized through ring-closing metathesis (RCM) of diallyl cross-bridged tetraamines 1 and 2 using Grubb's second-generation catalyst in the presence of tosic acid. Preliminary experiments on these compounds have shown the inner proton to be inert towards deprotonation in strongly basic solution. Adamanzanes 3 and 4 were also hydrogenated to give saturated analogs 5 and 6. These and other related results will be discussed.

1. Springborg, Johan, Dalton Trans., 2003, 1653-1665.