Synthesis of tetrasubstituted furans by sequential SmI2-promoted reduction and Pd-catalyzed cyclization

Tetrasubstituted furans are obtained in a one-pot, two-step sequence comprising SmI2-promoted reduction of a readily available 4,5-epoxyalk-2-ynyl ester followed by Pd(0)-promoted cyclization of the resulting 2,3,4-trien-1-ol in the presence of an aryl halide or triflate.