1.1: 100 percent / DIBAL-H / tetrahydrofuran / -78 °C 2.1: 54 percent / Ac2O; BF3*OEt2 / acetonitrile / 20 °C 3.1: MCPBA / CH2Cl2 / 10 h 3.2: 84 percent / H5IO6 / CH2Cl2 / 10 h 4.1: 95 percent / TiCl4 / ethanol 5.1: Pb(OAc)4 / methanol; CH2Cl2 6.1: HCl / Heating View Scheme