dimethylsulfide; ozone 1) CH2Cl2, -78 deg C, 1 - 5 min; Yield given. Multistep reaction;

diisobutylaluminium hydride in dichloromethane; toluene T=-78 - 0°C; 1.16667 h;

n-butyllithium in tetrahydrofuran; hexane T=-78°C; 0.25 h;

sodium hydroxide; dihydrogen peroxide in tetrahydrofuran T=20°C; 4 h;

n-butyllithium in tetrahydrofuran dissolution of stannanes in THF and cooling to -78°C (CO2/acetone), dropwise addn. of BuLi in hexane via syringe, stirring at -78°C for 15 min, quenching by rapidly addn. of satd. aq. NH4Cl, warming to room temp.; diluting in petroleum ether, washing with sat. NaCL-solution, drying over Na2SO4, removing solvent under reduced pressure;

1: With 1,3-bis(2,4,6-trimethylphenyl)-1,3-dihydro-2H-imidazol-2-ylidene in tetrahydrofuran T=25°C; 1 h; Inert atmosphere; 2: With n-butyllithium in tetrahydrofuran; hexane T=-78°C; Inert atmosphere;

1.1: dicyclohexylborane / tetrahydrofuran / 0 - 20 °C 1.2: 82 percent / AcOH / tetrahydrofuran / 6 h / 20 °C 2.1: CH2Cl2 / 6 h / 20 °C 3.1: 84 percent / CH2Cl2 / 0.5 h / 0 °C 4.1: 80 percent / sodium hydroxide; aq. H2O2 / tetrahydrofuran / 4 h / 20 °C View Scheme

1: CH2Cl2 / 6 h / 20 °C 2: 84 percent / CH2Cl2 / 0.5 h / 0 °C 3: 80 percent / sodium hydroxide; aq. H2O2 / tetrahydrofuran / 4 h / 20 °C View Scheme

1.1: n-BuLi / tetrahydrofuran; hexane / 0.5 h / 0 °C 1.2: 92 percent / tetrahydrofuran; hexane / 1.5 h / 20 °C 2.1: 68 percent / methyl iodide; CaCO3; H2O / acetonitrile / 16 h / 55 °C 3.1: 87 percent / DIBALH / CH2Cl2; toluene / 1.17 h / -78 - 0 °C View Scheme

1.1: 96 percent / BF3*OEt2 / CH2Cl2 / 26 h / 20 °C 2.1: n-BuLi / tetrahydrofuran; hexane / 0.5 h / 0 °C 2.2: 92 percent / tetrahydrofuran; hexane / 1.5 h / 20 °C 3.1: 68 percent / methyl iodide; CaCO3; H2O / acetonitrile / 16 h / 55 °C 4.1: 87 percent / DIBALH / CH2Cl2; toluene / 1.17 h / -78 - 0 °C View Scheme