1: 99 percent / 2M HCl, n-Bu3P / CH2Cl2 / a) 0 deg C, 2.5 h, b) RT, 6.5 h 2: N,N-diisopropylethylamine / CHCl3 / 2 h / 0 °C 3: 85 percent / trifluoroacetic acid, anisole / CH2Cl2; various solvent(s) / Ambient temperature 4: AgNO3, pyridine / H2O; methanol / 1 h / 0 °C 5: I2, KI, pyridine / methanol; aq. ethanol / 1 h View Scheme

1: 99 percent / 2M HCl, n-Bu3P / CH2Cl2 / a) 0 deg C, 2.5 h, b) RT, 6.5 h 2: N,N-diisopropylethylamine / CHCl3 / 2 h / 0 °C 3: 85 percent / trifluoroacetic acid, anisole / CH2Cl2; various solvent(s) / Ambient temperature 4: AgNO3, pyridine / H2O; methanol / 1 h / 0 °C View Scheme