Total synthesis of aspeverin via an iodine(III)-mediated oxidative cyclization.

The first total synthesis of aspeverin, a prenylated indole alkaloid isolated from Aspergillus versicolor in 2013, is described. Key steps utilized to assemble the core structure of the target include a highly diastereoselective Diels-Alder reaction, a Curtius rearrangement, and a unique strategy for installation of the geminal dimethyl group. A novel iodine(III)-initiated cyclization was then used to install the bicyclic urethane linkage distinctive to the natural product.