Palladium-catalyzed cyclization of cyclopropyl-substituted 1,6-enynes proceeded in
two ways depending on the presence or absence of a leaving group. In the presence
of the leaving group, 5.7-bicyclic trienes were obtained as the sole products; in
the absence of the leaving group, monocyclic trienes were isolated.
Key words
palladium - enynes - vinyl cyclopropanes - seven-membered rings - bicyclic compounds