1: 12-hydroxy-1-dodecanal dimethylacetal With sodium hydride in tetrahydrofuran; N,N-dimethyl-formamide T=20°C; 0.5 h; 2: methyl iodide in tetrahydrofuran; N,N-dimethyl-formamide T=20°C; 3 h;

1.1: 18 percent / PCC; Celite / CH2Cl2 / 1 h / 20 °C 2.1: 91 percent / p-TsOH / 20 °C 3.1: NaH in oil / dimethylformamide; tetrahydrofuran / 0.5 h / 20 °C 3.2: 64 percent / dimethylformamide; tetrahydrofuran / 3 h / 20 °C View Scheme

1.1: 91 percent / p-TsOH / 20 °C 2.1: NaH in oil / dimethylformamide; tetrahydrofuran / 0.5 h / 20 °C 2.2: 64 percent / dimethylformamide; tetrahydrofuran / 3 h / 20 °C View Scheme