MeLi in tetrahydrofuran; diethyl ether (N2), MeLi in Et2O added at -40°C, warmed up to room temp.; reduced in vacuo, sublimation;

1: boron trichloride / n-heptane; 1,2-dichloro-ethane / 72 h / 140 °C / Inert atmosphere; Sealed tube 2: hexane; n-heptane / -40 - 20 °C / Inert atmosphere View Scheme

1: anhydrous iron chloride; N,N,N',N,-tetramethylethylenediamine; diisobutylaluminium hydride; magnesium / tetrahydrofuran / -10 °C / Inert atmosphere 2: boron trichloride / n-heptane; 1,2-dichloro-ethane / 72 h / 140 °C / Inert atmosphere; Sealed tube 3: hexane; n-heptane / -40 - 20 °C / Inert atmosphere View Scheme

in hexane; n-heptane T=-40 - 20°C; Inert atmosphere;

in 1,1,2,3,4,4-hexachloro-1,3-butadiene byproducts: ClBMe2; thermolysis in hexachlorobutadiene (2 h, 45°C);

in benzene-d6 not isolated, detected by (13)C-NMR-spectroscopy;

in not given byproducts: CH3BCl2; Ar atmosphere;