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;