Enantioselective Copper‐Catalyzed Carboetherification of Unactivated Alkenes

Chiral saturated oxygen heterocycles are important components of bioactive compounds. Cyclization of alcohols onto pendant alkenes is a direct route to their synthesis, but few catalytic enantioselective methods enabling cyclization onto unactivated alkenes exist. Herein reported is a highly efficient copper‐catalyzed cyclization of γ‐unsaturated pentenols which terminates in CC bond formation, a net alkene carboetherification. Both intra‐ and intermolecular CC bond formations are demonstrated, thus yielding functionalized chiral tetrahydrofurans as well as fused‐ring and bridged‐ring oxabicyclic products. Transition‐state calculations support a cis ‐oxycupration stereochemistry‐determining step.