Electrocyclization Reactions of Benzannulated 2-Azaheptatrienyl- and 4-Azanonatetraenyllithium Compounds: Synthesis of N-Acylated 2,3-Dihydro-1<i>H</i>-benzo[<i>c</i>]azepines and a (5,6-Dihydrobenzocycloocten-5-yl)amine
2-acylated 2,3-dihydro-1H-benzo[c]azepines. This reaction is interpreted as a cascade involving a 1,7-electrocyclizationreaction and a subsequent 1,5-hydrogen shift. In contrast, 2-prop-l-enylbenzaldehyde N-allylimine leads to an N-acylated (5,6-dihydrobenzocycloocten-5-yl)amine upon deprotonation and addition of pivaloyl chloride. This transformation is interpreted as a reaction sequence consisting of a