Abstract In this article a regioselective domino metathesis reaction of unsymmetrical 7- oxanorbornenes, readily available by a tandem Ugi/Diels–Alder reaction as a key step, promoted by the Hoveyda–Grubbs second-generation catalyst in the presence of electron- rich vinyl acetate as a cross metathesis (CM) substrate is reported. The mechanism for the unusually high regioselectivity observed in the CM reaction was investigated, and a ...