1: With ozone in methanol T=-78°C; 2: With sodium tetrahydroborate in methanol T=0°C; 0.5 h; Further stages.;

1.1: tetrahydrofuran; diethyl ether / 1 h / 0 °C 2.1: O3 / methanol / -78 °C 2.2: 84 percent / NaBH4 / methanol / 0.5 h / 0 °C View Scheme

1.1: NaIO4; KH2PO4 / H2O / 9 h / 0 - 20 °C 1.2: 86 percent / Na2S2O3 / H2O / 0.25 h 2.1: 50 percent / tetrahydrofuran; hexane / 2 h / 20 °C 3.1: 47 percent / NMO / OsO4 / acetone; H2O / 5 h / 20 °C 4.1: NaIO4 / H2O / 0.5 h / 0 °C 5.1: 270 mg / NaBH4 / H2O / 0.75 h / 0 °C View Scheme