Hexanitrohexaazaisowurtzitane (HNIW) is a polycyclic cage nitramine and the most powerful high energy density compound (HEDC) ever tested. The authors have synthesized HNIW in a yield of 82% in a yield of 72% by the nitrolysis of tetraacetyldiformylhexaazaisowurtzitane (TADFIW) using a complex nitrating agent. Condensation of two benzyl groups at the six - membered ring of tetraacetyldibenzylhexaazaisowurtzitane (TADBIW) into two formyl groups in formic acid gave TADFIW in 72% yield. As described in the lit...