magnesium in tetrahydrofuran byproducts: MgBrCl; (Ar), Sb-compd. in THF added to Mg-chips, Me3SiCl added dropwise, stirred for 1 h; THF removed at 0.1 mmHg, washed several times with pentane, removed, distilled at 155°C/0.01 mmHg;

magnesium in tetrahydrofuran byproducts: MgBrCl; (Ar), Sb-compd. in THF added to Mg-chips, Me3SiCl added dropwise, stirred for 1 h; THF removed at 0.1 mmHg, washed several times with pentane, removed, distilled at 155°C/0.01 mmHg;