Intermolecular gold-catalyzed cycloaddition of alkynes with oxoalkenes

Gold(I) catalyzes a new intermolecular reaction of terminal alkynes with functionalized alkenes that gives 8-oxabicyclo[3.2.1]oct-3-enes by a [2+2+2] cycloaddition process in which two CC bonds and one CO bond are formed (see scheme).