in tetrahydrofuran 20 h reflux;

Mg; aq. HCl in diethyl ether; toluene under Ar, Mg was heated to 100 °C without solvent, ClCH2SiMe3 wasadded in ether at room temp., mixt. was cooled to 0 °C, stirred for 1 h, SnCl4 was added in toluene, mixt. was kept at 0 °C, refl ux for 8 h; mixt. was cooled in ice-bath, hydrolysed with 5 percent aq. HCl, layers were sepd., aq. layer was extd. 3 times with Et2O, combined org. phase was dried over Na2SO4, solvent was removed in vac., liquid was distd. at 35 °C/10 Hgmm, elem. anal.;

magnesium anschliessend mit SnCl4;

10 h, 150°C;

200-210°C, 16h;