Regio- and stereoselective ring-opening dimerization–cross-coupling metathesis of 7-oxanorbornene derivatives

A new metathesis-based route for the linking of two tetrahydrofuran moieties by an ethylene subunit has been developed. Treatment of an optically pure 2-substituted 7-oxanorborn-5-ene with Grubbsʹ ruthenium catalyst in the presence of allyl acetate afforded the product of two successive ring-opening metatheses and cross-metathesis in a highly regioselective fashion.