magnesium in tetrahydrofuran

sodium; magnesium bromide in tetrahydrofuran an active Mg prepd. by redn. of MgBr with Na in boiling THF reacted with 2,3-dimethylbutadiene and 3,4-dimethyl-1,1-diiodo-1-germacyclopent-3-ene;

in neat (no solvent) mixt. stirred with gentle heating for 0.5 h; addn. of pentane after cooling, filtration, removal of solvent;

GeI2 in n-heptane T=110°C; 24 h; Product distribution;

in n-heptane under N2, react. of GeI2 with CH2CMeCMeCH2 in heptane at 110°C for 1 d;

hydrogenchloride; sodium hydroxide in water diiodide treated with soln. of NaOH in H2O, neutralisation with dilute HCl, pptn., washed with ether, solvent removed from residue, residue wasshaken with large excess of concd. HCl; extn. (pentane), dried (over CaCl2), distn.;