1: 66 percent / I2, Ph3P, pyridine / toluene / 1 h / 60 - 70 °C 2: 93 percent / K2CO3 / methanol / 1.) 0 deg C, 30 min, 2.) r.t., 5 h 3: 93.5 percent / CuCN / tetrahydrofuran; diethyl ether / 0.5 h / -70 - -50 °C 4: aq. HCl / tetrahydrofuran / 16 h / Ambient temperature 5: 20percent aq. NaOH / methanol / 0.5 h / 100 °C View Scheme