chloroform; ammonium chloride in tetrahydrofuran soln. CHCl3/THF cooled to -90°C, addn. i-PrMgCl/THF over 15 min at -80°C, addn. Me3GeBr/THF (same temp.), mixt. stirred (-80°C, 0.5h), allowed to warm to room temp.; hydrolysed with satd. NH4Cl, organic layer separated, dried (Na2SO4), distilled, elem. anal.;