4 A molecular sieve in 1,2-dichloro-ethane T=70°C;

1: With ytterbium; methyl iodide in tetrahydrofuran; N,N,N',N',N'',N''-hexamethylphosphoric triamide T=20°C; 2 h; 2: With 1-naphthaldehyde in tetrahydrofuran T=20°C; 2 h; Further stages.;

samarium diiodide in tetrahydrofuran 17.5 h; Heating;