in tetrahydrofuran; dimethyl-ether T=-110°C;

in diethyl ether; hexane T=-78 - 20°C; 5 h;

in tetrahydrofuran; dimethyl-ether T=-135°C;

1: 73 percent / KMnO4; NaOH / H2O / 7 h / 0 - 20 °C 2: 67 percent / NaBH4 / methanol / 2 h / 0 °C 3: 59 percent / diethyl ether; hexane / 5 h / -78 - 20 °C View Scheme

1: 67 percent / NaBH4 / methanol / 2 h / 0 °C 2: 59 percent / diethyl ether; hexane / 5 h / -78 - 20 °C View Scheme

silver nitrate; triethylamine in water; acetonitrile 15 min, RT; 20 min, RT; 1 h, 45 deg C; Yield given;

1: 85 percent / 1.6 M n-BuLi / tetrahydrofuran; hexane / -78 deg C, 1 h; 10 min 2: 97 percent / dimethylformamide / 19.5 h / Heating 3: tetrahydrofuran / -78 deg C, 30 min; RT, 1 h 4: AgNO3, triethylamine / H2O; acetonitrile / 15 min, RT; 20 min, RT; 1 h, 45 deg C View Scheme

1: 97 percent / dimethylformamide / 19.5 h / Heating 2: tetrahydrofuran / -78 deg C, 30 min; RT, 1 h 3: AgNO3, triethylamine / H2O; acetonitrile / 15 min, RT; 20 min, RT; 1 h, 45 deg C View Scheme