1: 1) Ti(Oi-Pr)4, diethyl L-(+)-tartrate, tert-butyl hydroperoxide, 4 Angstroem molecular sieves / 1) CH2Cl2, -20 deg C, 20 h, 2) CH2Cl2, hexane, room temperature, 16 h 2: NaIO4 / tetrahydrofuran; H2O / 0.17 h / Ambient temperature 3: 4.34 g / CBr4, PPh3 / CH2Cl2 / 0.33 h / 0 °C 4: 87 percent / n-BuLi / tetrahydrofuran; hexane / 0.5 h / -78 °C View Scheme

ammonium cerium(IV) nitrate in water; acetonitrile T=20°C; 1 h;