Abstract A new ring system, a triazolobenzoxazepinone, has been synthesized in which the conformation of the 7-membered ring is rather rigidly imposed by the system. The conformation of the intermediates, nitro-and aminobenzoxazepinones, appear to be more sterically hindered than any precursors of the 7, 6-ring system. The formation of the 7, 6-and 7, 6, 5-ring systems and the preceding transition states must therefore be sterically ...
