Synthetic studies of 7-oxygenated aporphine alkaloids: preparation of (-)-oliveroline, (-)-nornuciferidine, and derivatives.

Abstract

7-Oxygenated aporphines 1-6 possessing anti-configurations have previously been reported. In order to explore their bioactivities, a synthesis was established by utilizing a diastereoselective reductive acid-mediated cyclization followed by palladium-catalyzed ortho-arylations. Moderate XPhos precatalyst loading (10 mol %) and short reaction times (30 min) were sufficient to mediate the arylations. Alkaloids 1-5 were successfully prepared, while (-)-artabonatine A was revised to syn-isomer 30. Consequently, (-)-artabonatine E likely also has a syn-configuration (31).