1: 99 percent / H2O2, LiOH / tetrahydrofuran; H2O / 20 h / 20 °C 2: 87 percent / PhSO2Cl, pyridine / 16 h / -20 °C 3: 100 percent / aq. HF / acetonitrile / 2 h / 20 °C 4: H2 / (Ph3P)3RhCl / benzene / 2 h / 20 °C / 760 Torr View Scheme