1: ethyl 2-benzenesulfonyldecanoate With sodium hexamethyldisilazane in tetrahydrofuran T=-78°C; 1 h; 2: methyl iodide in tetrahydrofuran T=-78 - -40°C;

1.1: NaHMDS / tetrahydrofuran / 1 h / -78 °C 1.2: 96 percent / tetrahydrofuran / -78 - -40 °C 2.1: 99 percent / DIBAL-H / toluene / 0.33 h / -78 °C View Scheme