Iminophosphoranes 4, derived from ethyl a-azido-2-(allyloxy)-3-methoxycinnamates, react with ketenes to give the corresponding ketene imines, which by thermal treatment at 150- 160 OC undeqo a consecutive electrocyclic ring cloeure/Claisen rearrangement/second ring cloeum/double aromatization proms to give boquinoline derivativea 7 and/or the previously unknown fluoreno [2, 3, 4-i~~ imquinolines 9 in moderate yields. S ily, ...