n-butyllithium in tetrahydrofuran; hexane T=-78 - 20°C; 3.75 h;

1: p-bromophenyl bromide With n-butyllithium in tetrahydrofuran; hexanes T=-78°C; 0.5 h; 2: oxetan-3-one in tetrahydrofuran; hexanes T=-78 - 20°C; 3: With ammonium chloride in tetrahydrofuran; hexanes; water T=20°C;