1: in tetrahydrofuran T=-78°C; Inert atmosphere; 2: With hydrogenchloride in tetrahydrofuran; water chemoselective reaction;

boron trifluoride diethyl etherate T=20°C; 72 h;

in tetrahydrofuran T=-78°C; Inert atmosphere; chemoselective reaction;

in dichloromethane addn. of BF3*OEt2 to soln. of 1,3-diketone in dichloromethane at room temp., reaction mixture remained for 72 h at room temp.; evapn. in vac., residue suspended in water, solid material filtered off and recryst. from toluene; elem. anal.;

boiling of the tetralone dissolved in acetic anhydride in presence of excess of BF3 etherate.;