carbon tetrabromide; triphenylphosphine in dichloromethane T=0°C; 0.666667 h;

1: 85 percent / CBr4, PPh3 / CH2Cl2 / 0.67 h / 0 °C 2: K2CO3, NaI, CuI / dimethylformamide / 6 h / 20 °C 3: TsOH / methanol / 2 h / 20 °C 4: 67 percent / KOH, K2CO3 / H2O; acetone / 1.5 h / 20 °C 5: K2CO3, NaI, CuI / dimethylformamide / 6 h / 20 °C 6: 5percent aq. NaOH / methanol / 4 h / 20 °C 7: 85.5 percent / H2 / Pd/CaCO3/Pb View Scheme

1: PBr3, Py / diethyl ether 2: (i) EtMgBr, THF, (ii) /BRN= 1840948/, CuCl, (iii) TsOH, MeOH 3: PBr3, Py / diethyl ether 4: (i) EtMgBr, Et2O, (ii) /BRN= 1841586/, CuCl 5: (i) H2, Lindlar catalyst, EtOH, (ii) /BRN= 102415/, MeOH, Et2O View Scheme

1: 91 percent / LiAlH4 / diethyl ether / 5 h / 25 °C 2: 76 percent / dimethyl(S,S)(-)-tartarate 3: 90 percent / H2 / Lindlar / tetrahydrofuran / 760 Torr 4: 84 percent / O2 / oxidation with Collins reagent 5: 94 percent / tetrahydrofuran / -78 deg C, 10 min,; and then from -78 deg Cto 0 deg C over 1 h. 6: 84 percent / acetic acid; acetonitrile; H2O / 6 h / 25 °C 7: triphenylphosphine, imidazole, I2, diisopropylamine / diethyl ether; acetonitrile / 0.67 h / 25 °C 8: acetonitrile / 16 h / 60 °C 10: 1.) potassium isopropoxide; 2.) base / 1.) 0 deg C, 1 h; 2.) hydrolysis View Scheme