1,8-diazabicyclo[5.4.0]undec-7-ene in benzene T=70 - 80°C; 3 h;

1: 79.1 percent / potassium carbonate / 1.5 h / Ambient temperature 2: 20.4 percent / LiN(SiMe3)2 / tetrahydrofuran; hexane / 4 h / -30 °C 3: 1.) sodium hydride / 1.) THF, RT, 20 min, 2.) THF, reflux, 5h 4: 100 percent / 30percent aq. hydrogen peroxide / methanol / 120 h / Ambient temperature 5: 44.5 percent / trifluoroacetic anhydride, 2,6-lutidine / acetonitrile / 4 h / -25 °C 6: 91 percent / iodine / 15 h / Ambient temperature 7: 32.3 percent / 10percent aq. hydrochloric acid / tetrahydrofuran / 55 h / Ambient temperature 8: 1.) 2,6-lutidine, trifluoroacetic anhydride; 2.) potassium carbonate / 1.) acetonitrile, -30 deg C, 2h; 2.) acetonitrile, RT, 1 h 9: 76.7 percent / iodine / 24 h / Ambient temperature View Scheme