Photolysis or flash vacuum clo[3.2.21non-5-ene lJ, a was trapped with methanol. pyrolysis of 1-bicycloC3.2.1loctylazide 2 yields 6-azabicystrained bridgehead imine, which could not be isolated but Renewed interest in the synthesis and chemistry of bridgehead olefins (Bredt-olefins)* has been aroused since the first preparation of bicyclo[3.3.1Jnon-1-ene 1 fifteen years ago.3 At that time Wiseman put forward the hypothesis that bridgehead olefins may be compared in strain and reactivity with the corresponding monocyclic (E)-cycloalkenes, from which they are formally derived by bridging. Bredt's rule and Wiseman's stability criterion should also be applicable to unsaturated bridgehead compounds containing heteroatoms, e.g. bridgehead imines. Indeed, whereas the 2,5-ethylene-bridged (E)-1-azacyclohex-1-ene z5 and the (E)-1-azacycloheptenes z5, 6 4 , and 5 cannot be isolated, but _' may be trapped with methanol, the bridged (E)-1-azacyclooctene 5 is stable at room temperature.8 A recent report' describes the synthesis and reactions of two tricyclic bridgehead imines 7 and S with bis-homoadamantane skeleton, both of which are formal bridged (E)-l-azacyclooctenes. 18 Imines L and 8 have not been isolated pure, -but they seem to survive for a limited period of time at ordinary temperature. 1