A Strategy for the Convergent and Stereoselective Assembly of Polycyclic MoleculesPublic Deposited
Fused polycyclic scaffolds with three-dimensional complexity from an array of stereocenters compose the core structures of countless natural product families with a variety of desirable biological activity. The development of synthetic methods and strategies to afford rapid access to these structures is essential to expose a wealth of untapped biological potential. Oxidative enolate coupling is a powerful tool in the context of this task, forging a new carbon–carbon bond between two fragments. This reaction serves as the foundation for the strategy developed herein, facilitating the convergent and stereoselective construction of fused polycyclic scaffolds when employed in an oxidative coupling–ring-closing metathesis sequence. The established tandem successfully assembled several fused structures with four contiguous stereocenters, varying in substitution pattern and carbocyclic composition. Demonstrated selective manipulations of the prepared compounds reinforced the value of the strategy to complex molecule synthesis. The developed strategy was successfully applied to the concise synthesis of marine diterpenoid (+)-7,20-diisocyanoadociane. Execution of the established sequence enabled the convergent construction of much of the natural product’s all-trans perhydropyrene core structure, while exploiting the pseudo-symmetry within the molecule to amplify the efficiency of the final stages of the synthesis.