magnesium in tetrahydrofuran a soln. of ditin oxide in dry THF was added dropwise to a suspn. of a magnesium powder, activated by BrCH2CH2Br or I2, in dry THF, mixt. was heated at reflux for 15 h; petroleum ether was added, filtered, solvents evapd., residue was distilled;

formic acid in not given byproducts: CO2, H2O; 100°C, stirring (4 h), then 200°C (200 Torr, 4 h), addn. of further formic acid, 100°C (30 min); cooling to room temp., decantation, addn. of petroleum ether, filtration, evapn., distn.; mixt. of products detd. by (119)Sn-NMR spectroscopy and liquid chromy.;

sodium borohydride in tetrahydrofuran