Studies directed towards the total synthesis of (+)-sieboldine A

Abstract

Progress towards the total synthesis of sieboldine A is described. This synthetic approach uses a nickel-catalyzed alkyne-ketone reductive cyclization to form the hydrindane core of the natural product in good yield and with excellent diastereoselectivity about the newly formed tertiary allylic alcohol ... The hydrindane product from this reductive cyclization can be transformed into the tetracyclic N,O-acetal which is two steps removed from the natural product 1. Efforts directed towards completion of the synthesis of 1 via a direct late-stage amine oxidation are presented ...