Me3SiCH2K in tetrahydrofuran; pentane T=-40°C; 24 h; two equivalent of trimethylsilylmethyl-potassium;

sodium hydroxide; N-benzyl-N,N,N-triethylammonium chloride in water T=40°C; 4 h;

1: 36 percent / benzyltriethylammonium chloride, NaOH / H2O / 4 h / 40 °C 2: 51 percent / trimethylsilylmethyl-potassium / pentane; tetrahydrofuran / 24 h / -40 °C / two equivalent of trimethylsilylmethyl-potassium View Scheme

in methanol Irradiation;