in benzene byproducts: Et2GeCl2; Ar-atmosphere; dropwise addn. of 0.5 equiv. GeCl4 to Et2Ge-derivative atroom temp., refluxing for 3 h; concn., pptn. on pentane addn., collection (filtration), drying (vac.);

in N,N-dimethyl-formamide Ar-atmosphere; dropwise addn. of 1 equiv. quinone to Ge-compd. (pptn.);

in tetrahydrofuran Irradiation (UV/VIS); Ar-atmosphere; UV lamp (254 nm), 50 min; solvent removal; product mixt. not sepd., detd. by NMR spectroscopy;