PALLADIUM(0)-CATALYZED DOMINO CYCLIZATION-CARBONYLATION OF ALKENYL-ALLENYL-ALLYLIC ACETATE

The Pd(0)-catalyzed domino cyclization-carbonylation of 5,8-dimethyl-5-(1,2-propadienyl)-2,8-nonadienyl acetate (7) was achieved at a rather higher temperature. The tricyclic and tetracyclic products, 15 and 16, were produced in 77% combined yield via five and six consecutive carbon–carbon bond formations, each step proceeding in > 94% yield.