1.1: TFA / CH2Cl2 / 20 °C 2.1: NaCNBH3; 4 Angstroem molecular sieves / methanol / 0 °C 3.1: TsOH / CH2Cl2 / 20 °C 3.2: dimethyldioxirane / CH2Cl2 / 20 °C 3.3: 45 percent / DBU / CH2Cl2 / 20 °C 4.1: 98 percent / NaBH4 / ethanol / 80 °C 5.1: NaIO4 / tetrahydrofuran; H2O / 20 °C 5.2: 64 percent / CH2Cl2 / 70 °C 6.1: 50 percent / Ph3SiOReO3; TsOH / benzene / 60 °C View Scheme