Enantioselective synthesis of medium-ring heterocycles, tertiary ethers, and tertiary alcohols by Mo-catalyzed ring-closing metathesis.

The Mo-catalyzed asymmetric ring-closing metathesis (ARCM) of various achiral trienes leads to the formation of medium-ring unsaturated heterocycles in high yield and with excellent enantioselectivity. Reactions may be carried out on gram scale and in the absence of solvent. The unsaturated siloxanes obtained enantioselectively can be readily functionalized to obtain synthetically useful and difficult-to-access tertiary alcohols.