hydrogen bromide in tetrahydrofuran org. compd. addn. slowly into flask with Mg under N2, mixt. stirring 1 h, Grignard reagent soln. pouring onto cold Hg-salt soln., mixt. pouring onto ice after 2 h, acidifying (HBr), mixt. extn. (Et2O); extracts washing (10percent HBr), sepn., drying (MgSO4), solvent evapn.;

hydrogen bromide in tetrahydrofuran org. compd. addn. slowly into flask with Mg under N2, mixt. stirring 1 h, Grignard reagent soln. pouring onto cold Hg-salt soln., mixt. pouring onto ice after 2 h, acidifying (HBr), mixt. extn. (Et2O); extracts washing (10percent HBr), sepn., drying (MgSO4), solvent evapn.;