UNSATURATED FLUOROCOMPOUNDS ARE PRODUCED BY A COMBINATION OF STEPS COMPRISING (A) REACTING A PERHALOETHYLENE WITH AN UNSATURATED COMPOUND TO PRODUCE A CORRSPONDING CYCLOBUTANE DERIVATIVE TO OBTAIN THE CORRESPONDING PERFLUOROCYCLOBUTANE DERIVATIVE, (C) PYROLYZING SAID PERFLUOROCYCLOBUTANE DERIVATIVE TO FORM THE UNSATURATED PERFLUOROCOMPOUND AND SAID STARTING PERHALOETHYLENE, AND (D) RECYCLING AT LEAST A PORTION OF SAID PERHALOETHYLENE FORMED IN SAID STEP (C) TO SAID STEP (A).