BuLi in tetrahydrofuran; hexane byproducts: butane; under N2, -78°C, warmed to 0°C, recooling to -78°C, then addn. of Mn(CO)5Cl, stirring at -78°C; solvents replaced by dioxane/Et2O 1:1, addn. of NH4Cl, passed over silica gel column, after solvent removal taken up in toluene, chromy. (silica gel, hexane/Et2O 2:1);