Divergent Total Syntheses of (−)-Galanthamine, (−)-Narwedine, (−)-Lycoraminone and (−)-Lycoramine, and Formal Syntheses of (−)-Morphine and (−)-Codeine

Polycyclic alkaloids have attracted great attention from the synthetic community because of their interesting structures and biological activity. Herein, we report the divergent syntheses of several galanthamine- and morphine-type alkaloids that share a fused 6/5/6 cis-hydrodibenzofuran core. The key transformation in these syntheses features a Pd-catalyzed Heck/aminocarbonylation reaction, which allowed for the rapid assembly of the fused 6/5/6 cis-hydrodibenzofuran core of these alkaloids with excellent diastereoselectivity. This approach provides a new strategy for the synthesis of other polycyclic alkaloids with similar structural characteristics.