The photolysis of (2)-bis (1-methylethy1) diazene N-oxide [1-(2)] gave ring closure to oxadiaziridine 2 as the principal product accompanied by minor amounts of deoxygenation. Azoxyalkane 1-(E) was not obtained by direct photolysis of 1-(2) owing to an unfavorable photoequilibrium strongly favoring 1-(2); 1-(E) was obtained by thermolysis of 2 and, alternately, by peroxy acid oxidation of (2)-azoisopropane.(2)-Cyclohexylmethyldiazene 1- ...