PROGRESS TOWARDS THE TOTAL SYNTHESIS OF STEMOCURTISINE VIA CARBONYLATIVE LACTONIZATION STRATEGY

Carbon monoxide is a cheap and abundant one carbon source. Insertion of carbon monoxide using palladium catalysts, also known as carbonylation reactions, has been developed in the last few decades. In addition, cyclopropanols are unique structures that are often benchtop stable and are synthetically useful due to the inherent ring strain and the vast number of functional groups it can be transformed into. For example, our group, a transformation from a hydroxycyclopropanol to a THF fused bicyclic lactone was developed. Herein, I discuss the synthetic applications of this transformation in natural product synthesis towards the Stemona alkaloid, Stemocurtisine.

The total synthesis of stemocurtisine was attempted with the Kulinkovich reaction followed by the palladium catalyzed carbonylation reaction developed in our group as the key reaction. While the general skeleton was developed, one key C-N bond was not able to be formed. Although the synthesis was not able to be completed, the skeleton of stemocurtisine, including the tricyclic core was synthesized.