The first total syntheses of pseudorigidols A and B are reported. Our syntheses employ a rhodium-catalyzed C-H insertion reaction to build the tricyclic core. The catalyst screen revealed the influence of a remote stereogenic center on the diastereoselectivity of the insertion. Using two different catalysts, we were able to synthesize the two natural products with high diastereoselectivity. These results will lay the foundation for further studies on the influence of remote stereogenic centers.
Ung et al. (Tue,) studied this question.