1: 79 percent / 0.5 h / 140 °C 2: 1.) (n-Bu)3P 2.) MeI / 1.) 140 deg C 2.) petroleum ether (60-70 deg C) 3: 57 percent / tetracyanoethylene, ozone / ethyl acetate / 0.5 h / -78 °C View Scheme