Unusual Intramolecular Cyclization of Tris(β-oximinoalkyl)amines. The First Synthesis of 1,4,6,10-Tetraazaadamantanes

An unusual intramolecular cyclization of tris(β-oximinoalkyl)amines 1 into 4,6,10-trihydroxy-1,4,6,10-tetraazaadamantanes 2 was discovered. Compounds 2 are related to a previously unknown type of heteroadamantanes that contain the cage isomeric to urotropin. A simple three-step synthesis of tetraazaadamantanes 2 and their N-substituted derivatives 3 and 4 from ammonia and aliphatic nitro compounds via the intermediacy of available tris-oximes 1 was developed.