1: 83 percent / N2H4*H2O / methanol / 21.5 h / Heating 2: diethyl ether / 1) 0 deg C, 1 h, 2) rt, 19.5 h 3: 97 percent / 2 M KOH / methanol / 4 h / Ambient temperature 4: 83 percent / Ac2O / tetrahydrofuran / 120 h / Ambient temperature 5: 13 percent / air / various solvent(s) / 2 h / Heating 6: 54 percent / Ph3P / 1.5 h / Heating View Scheme

triphenylphosphine; diethylazodicarboxylate in tetrahydrofuran 26 h; Ambient temperature;

1: 99 percent / CeCl3*7H2O, NaBH4 / methanol / 26 h / Ambient temperature 2: 71 percent / Ph3P, diethyl azodicarboxylate / tetrahydrofuran / 26 h / Ambient temperature View Scheme