magnesium in tetrahydrofuran; diethyl ether di-Grignard reagent prepd. from Br(CH2)5Br and Mg in THF added to Me2GeCl2 dissolved in ether over 30 min, stirred with reflux for 4 h, hydrolyzed; extd. with ether, dried over CaCl2, fractionally distd.; elem. anal.;

azobisisobutyronitrile or dibenzoyl peroxide in benzene hydrogermane, radical initiator, and benzene sealed after degassing in Pyrex tube, kept at 42°C for 15 h for AIBN or at 80°C for 20 h for BPO; sepd. by preparative GLC;