The transition metal-catalyzed asymmetric ring-opening(ARO) reactions of oxa-and azabicyclic alkenes have emerged as an important method for the construction of carbon-carbon and carbon-heteroatom bonds.We previously reported the iridium-catalyzed ARO reactions of oxa-and azabicyclic alkenes with various nitrogen-containing nucleophiles including aliphatic amines,aromatic amines and piperazines,affording hydronaphthalenes in good yields with excellent enantioselectivities.To the best of our knowledge,however,the ARO reactions of oxabicyclic alkenes with Grignard Reagents by iridium remain underdeveloped.Herein,we report a new,versatile,and highly efficient iridium-catalyzed ARO of oxabenzonorbornadienes with Grignard reagents.The reactions gave the products in excellent yileds(up to 98％).