Stereoselective Synthesis of Highly Substituted O-Heterocycles via Matteson Homologation: A Ring-Closing Metathesis Approach.

Matteson homologations of chiral boronic esters with the aid of unsaturated nucleophiles are powerful for gaining access to a range of different O-heterocycles via subsequent ring-closing metatheses. Using this protocol, six- to eight-membered rings become available and almost any position of the ring can be substituted and/or functionalized.