IntramolecularDiels-Alderreaction of l-azadienes was conducted by heating the α,β-unsaturated amides (2a ∼ d and 6) in the presence of trimethyl- chlorosilane, triethylamine and zinc chloride to give benzo- and indolo[a]- quinolizidines (5a ∼ e and 7).
Stereocontrolled construction of octahydroquinolizines, octahydroindolizines, hexahydrobenzo[a]quinolizines, and an octahydroindolo[2,3-a]quinolizine by an intramolecular double Michael reaction: synthesis of (±)epilupinine
trifluoromethanesulphonate in the presence of triethylamine at –78 to 20 °C. A simple synthesis of an alkaloid, (±)-epilupinine, was accomplished. Hexahydrobenzo[a]-quinolizin-4-ones and an octahydroindolo[2,3-a]quinolizin-4-one were also constructed by the same method.