hydrogenchloride; sulfuric acid; ammonium chloride in tetrahydrofuran; diethyl ether prepn. of MeMgI in dry Et2O, cooling ester in Et2O to -20°C, addn. of MeMgI (temp. <-15°C), heating to 10°C (20 min), addn. of aq. NH4Cl (pH 7), combining org. layer and extracts (Et2O), removal of Et2O, boiling with H2O/H2SO4 (1 h); cooling, addn. of Et2O, sepn. of Et2O layer, pptn. by acidifying (2 N HCl, pH 2), filtration, washing (H2O), recrystn. (EtOH); elem. anal.;

thionyl chloride in benzene byproducts: HCl; dissolving acid in dry benzene, addn. of freshly distd. SOCl2, boiling (2 h) with passage of argon stream; removal of solvent, distn. in vac.;