Enantioselective Total Synthesis of the Nonisoprenoid Sesquiterpene (-)-Kumausallene.

An acyl radical cyclization to form the bicyclic core of (-)-kumausallene (1) was the key feature in the 14-step, enantioselective synthesis. This work demonstrates that the bromoallene unit is robust enough to withstand multiple synthetic operations and provides the unambiguous assignment of the absolute configuration of the bromoallene.