Asymmetric Total Synthesis of (-)-Aspidophylline A.

An asymmetric total synthesis of (-)-aspidophylline A has been accomplished. The key transformations include an asymmetric hydride transfer hydrogenation of an α,β-acetylenic ketone and a cationic gold(I)-catalyzed 6-exo-dig cyclization involving an alkynylindole/aminal formation cascade, which enables stereoselective establishment of the requisite quaternary carbon center.