Selective Synthesis of Furan‐3(2H)‐one Fused Seven, Eight, or Nine‐Membered Ring from the Reaction of Diynone and Cyclic β‐Keto Ester

A domino reaction of diynone and cyclic β‐keto ester has been disclosed. This reaction provides a new strategy for the synthesis of a series of furan‐3(2H)one fused seven‐, eight‐, or nine‐membered ring with good stereoselectivity and atom economy.