Synthesis of the First Examples of Fully Unsaturated Monocyclic 1,4=Oxazepines ... Jyoji Kurita, Kuniyoshi Iwata, and Takashi Tsuchiya* School of Pharmacy, Hokuriku University, Kanagawa-machi, Kanazawa 92G 1 1, Japan ... Photolysis of the 3-aza-7-oxatricyclo[4.1.0.0* r~]hept-3-enes (3), prepared from pyridines via five steps, results in ring expansion to give the novel lt4-oxazepines (4). ... There is considerable current interest in the synthesis of new ...