(+)-Desoxoprosopinine: A Model for the Total Asymmetric Synthesis of Prosopis Alkaloids

Abstract

This work develops a general synthesis of the Prosopis africana alkaloids, using a chiral auxiliary-mediated process. Enantiopure N-acyldihydropyridones were produced and used as intermediates, targeting (+)-desoxoprosopinine as a synthetic model for those alkaloids. The orientation of all three stereocenters was highly controlled, with the synthesis of intermediate 75, just short of the target, in 7steps with a 13.8% overall yield.