n-butyllithium; methyl iodide in tetrahydrofuran; N,N,N',N',N'',N''-hexamethylphosphoric triamide; hexane Addn. of n-BuLi (in hexane) to a soln. of Ge-compound in THF-HMPA (Ar, -78°C), stirring (30 min), dropwise addn. of a soln. of MeI in THF, stirring (30 min), warming to 0°C.; Workup (AcOEt, aq. HCl), tlc (SiO2) gives a 3:7 mixt in 75 percent yield.;