Heteroadamantanes and their derivatives. 9. Synthesis of 1,5-dinitro-3,7-diazabicyclo[3.3.1]nonane and derived 2,2-disubstituted 5,7-dinitro-1,3-diazaadamantanes

Heating 1,5-dinitro-3,7-di(tert-butyl)-3,7-diazabicyclo[3.3.1]-nonane with concentrated hydrobromic acid gives 1,5-dinitro-3,7-diazabicyclo[3.3.1]nonane. Cyclization of the latter with various aldehydes and ketones gave a series of 2,2-disubstituted 5,7-dinitro-1,3-diazaadamantanes. The behavior of the synthesized compounds under electron impact has been studied.