Copper Salt Catalyzed Synthesis of Functionalized 2 H ‐Pyranes

A copper‐catalyzed reaction between terminal alkynes, oxiranes, and malonitrile has been described. In this transformation, copper acetylide was attacked on oxiranes to form homopropargyl alkoxy‐copper intermediate that was further transferred to 2 H ‐pyrane skeletons by reaction with malonitrile. We found that the reaction was not productive without hexafluoroisopropanol.