synthesis of structurally different systems including the monocyclic derivatives 17 and 18, the bicyclic azepinones 10a–d, and the tricyclic heterocycles 37–40, 42, 43, 45, 47, and 48. In addition, the applicability of the reaction principle was demonstrated through the preparation of the benzo-piperidino compound 52 which acts as a model compound for the alkaloid astrocasine (53). A multistep reaction mechanism