Unprecedented alkene exchange by reversible alkene extrusion from platinaoxtanes has been observed. Addition of catalytic amount of electrophilic Pt complexes, HOTf, Ag+, BF3(best) to the reaction results in dramatic rate enhancements. The reactions are catalyzed by coordination of the platinaoxetane oxygen atom to Lewis acids. A single Lewis acid appears to be inadequate and two Lewis acids are needed for alkene extrusion and exchange to occur.