Platinum-Catalyzed Tandem Cycloisomerization Reaction of Benzoendiynyl Esters: Regioselective Long-Range 1,5-Acyl Migration

A Pt<sup>II</sup>-catalyzed intramolecular chemo- and regioselective pentannulation/long-range 1,5-acyl migration reaction is described. This cascade cycloisomerization protocol produces a wide variety of benzofulvene diketones in good to excellent yields with exclusively the <i>Z</i> configuration of the exocyclic double bond of the final product. The <sup>18</sup>O isotope experiment together with <sup>13</sup>C NMR, HRMS, and HMBC analyses confirmed an interesting long-range acyl rearrangement process in this transformation.