n-butyllithium; potassium carbonate 1.) MeCN; 2.) THF, -60 deg C; Yield given. Multistep reaction;

1: With potassium carbonate in acetonitrile 2: With n-butyllithium in diethyl ether; hexane T=-78 - 20°C; 3: With methanol T=-78°C; Further stages.;

1: (Tributylstannyl)methyl methanesulfonate; N-Benzylbenzylamine in acetonitrile T=50°C; 24 h; 2: With n-butyllithium in tetrahydrofuran; hexane T=-45°C; 0.25 h; Inert atmosphere; 3: benzaldehyde in tetrahydrofuran; hexane T=-45°C;