1: triphenyl-methyl-phosphonium iodide With potassium tert-butylate in tetrahydrofuran 0.5 h; 2: C16H26O2Si in tetrahydrofuran 1 h; Reflux;

1.1: n-butyllithium / tetrahydrofuran; hexane / 0.33 h / -78 °C 1.2: -78 - 20 °C 1.3: 0 °C 2.1: potassium tert-butylate / tetrahydrofuran / 0.5 h 2.2: 1 h / Reflux View Scheme

tetrabutyl ammonium fluoride in tetrahydrofuran T=20°C;