1: Methyltriphenylphosphonium bromide With n-butyllithium in tetrahydrofuran; hexane T=0°C; 0.5 h; 2: (E)-4-(tert-butyldiphenylsilyloxy)-2-methylbut-2-enal in tetrahydrofuran; hexane T=0 - 20°C; 1 h;

1.1: imidazole / CH2Cl2 / 0.33 h 2.1: tert-butyl hydroperoxide; SeO2 / CH2Cl2; H2O / 48 h / 20 °C 2.2: 14.41 g / NaBH4 / methanol; CH2Cl2; H2O / cooling 3.1: 82 percent / MnO2 / CH2Cl2 / 36 h / 20 °C 4.1: n-butyllithium / tetrahydrofuran; hexane / 0.5 h / 0 °C 4.2: 94 percent / tetrahydrofuran; hexane / 1 h / 0 - 20 °C View Scheme

1.1: tert-butyl hydroperoxide; SeO2 / CH2Cl2; H2O / 48 h / 20 °C 1.2: 14.41 g / NaBH4 / methanol; CH2Cl2; H2O / cooling 2.1: 82 percent / MnO2 / CH2Cl2 / 36 h / 20 °C 3.1: n-butyllithium / tetrahydrofuran; hexane / 0.5 h / 0 °C 3.2: 94 percent / tetrahydrofuran; hexane / 1 h / 0 - 20 °C View Scheme

1.1: imidazole / CH2Cl2 / 0.33 h 2.1: tert-butyl hydroperoxide; SeO2 / CH2Cl2; H2O / 48 h / 20 °C 2.2: 14.41 g / NaBH4 / methanol; CH2Cl2; H2O / cooling 3.1: 82 percent / MnO2 / CH2Cl2 / 36 h / 20 °C 4.1: n-butyllithium / tetrahydrofuran; hexane / 0.5 h / 0 °C 4.2: 94 percent / tetrahydrofuran; hexane / 1 h / 0 - 20 °C View Scheme

1.1: 82 percent / MnO2 / CH2Cl2 / 36 h / 20 °C 2.1: n-butyllithium / tetrahydrofuran; hexane / 0.5 h / 0 °C 2.2: 94 percent / tetrahydrofuran; hexane / 1 h / 0 - 20 °C View Scheme