1: 99 percent / HCl / 1 h / Ambient temperature 2: 90 percent / sodium methoxide / methanol / 3 h / 0 °C 3: 97.5 percent / aq. KOH / 2-ethoxy-ethanol / 3 h / Heating 4: oxalyl chloride / CH2Cl2 / 3 h / Ambient temperature 5: AlCl3 / CS2 / 1.) 0 deg C, 1h, 2.) reflux, 30 min 6: 79 percent / NaBH4 / tetrahydrofuran; methanol / 0.5 h / Ambient temperature 7: 70 percent / p-toluenesulfonic acid / benzene / 0.5 h / Heating 8: 79 percent / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone / benzene / 0.17 h / Heating View Scheme

diethyl ether; triphenylmethyl-sodium Herstellung von 11H-Benzo<b>fluoren-11-<14C>carbonsaeure; anschliessend Behandeln mit 14CO2;

1: palladium/charcoal; ethanol / Hydrogenation 2: trityl sodium; diethyl ether / Herstellung von 11H-Benzo<b>fluoren-11-<14C>carbonsaeure; anschliessend Behandeln mit 14CO2 View Scheme

hydrogenchloride 1 h; Ambient temperature;

1: 99 percent / HCl / 1 h / Ambient temperature 2: 90 percent / sodium methoxide / methanol / 3 h / 0 °C 3: 97.5 percent / aq. KOH / 2-ethoxy-ethanol / 3 h / Heating View Scheme

1: 99 percent / HCl / 1 h / Ambient temperature 2: 90 percent / sodium methoxide / methanol / 3 h / 0 °C 3: 97.5 percent / aq. KOH / 2-ethoxy-ethanol / 3 h / Heating 4: oxalyl chloride / CH2Cl2 / 3 h / Ambient temperature 5: AlCl3 / CS2 / 1.) 0 deg C, 1h, 2.) reflux, 30 min 6: 79 percent / NaBH4 / tetrahydrofuran; methanol / 0.5 h / Ambient temperature 7: 70 percent / p-toluenesulfonic acid / benzene / 0.5 h / Heating View Scheme

1: 99 percent / HCl / 1 h / Ambient temperature 2: 90 percent / sodium methoxide / methanol / 3 h / 0 °C 3: 97.5 percent / aq. KOH / 2-ethoxy-ethanol / 3 h / Heating 4: 80 percent / HCl / 0.33 h / 0 °C View Scheme