1: benzene / 72 h / Heating 2: triethylamine / benzene; tetrahydrofuran / 4 h / Ambient temperature 3: triethylamine / benzene; tetrahydrofuran / 64 h / Ambient temperature 4: 97 percent / aq. 1 N hydrochloric acid / acetic acid / 0.75 h / Heating View Scheme

(i) NaH, THF, (ii) /BRN= 389456/; Multistep reaction;

(i) NaH, THF, (ii) /BRN= 2719420/; Multistep reaction;