magnesium in tetrahydrofuran byproducts: MgClBr; Sonication; the mixt. of magnesium, germane and halogen-compound in THF was sonicated for 2 h (inert atm.); the mixt. was washed with satd. soln. of NaCl, extd. with diethyl ether,the organic layer was dried over MgSO4, the solvent was removed under r educed pressure, column chromy. (petroleum ether-diethyl ether 95/5);

in diethyl ether addn. of Et3GeBr soln. to a soln. of benzylmagnesium bromide, refluxingovernight; hydrolyzing (ice water), column chromy. (silica gel, hexane-ether), fractional distn;

in hexane byproducts: toluene; Irradiation (UV/VIS); irradn. with a medium-pressure Hg-lamp for 3 min under Ar; preparative GLC, GC-Mass;

in hexane 0.05 h; Irradiation; Yield given;

in hexane Irradiation (UV/VIS); further products; irradn. with medium-pressure Hg-lamp for 2 h under Ar; preparative GLC;