The [3,5,5,7] tetracyclic skeleton of echinopines has been stereoselectively accessed through a gold(I)-catalyzed alkoxycyclization of cyclopropyl-tethered 1,6-enynes. The key bicycle[4.2.1]nonane core of the enyne precursors was readily assembled by means of a Co-catalyzed [6+2] cycloaddition. Furthermore, the attempted alkoxycyclization of 1,5-enyne substrates revealed an uncovered cyclopropyl rearrangement that gives rise to [3,6,5,7] tetracyclic structures.
Ready Access to the Echinopine s Skeleton via Gold(I) – Catalyzed Alkoxycyclization s of Enynes
GO TO OPEN ACCESS The Journal of Organic Chemistry 2016, 81, 8444-8454.