1: 1.) LDA / 1.) 0 deg C, THF, 1 h 2.) -78 deg C, THF, 4 h 2: 80 percent / activated MnO2 / CH2Cl2 / 2 h 3: 90 percent / ZnCl2, DIBAL / tetrahydrofuran / 1 h / -78 °C 4: 65 percent / Al-Hg / tetrahydrofuran; H2O / 12 h / Ambient temperature 5: 1.) Me3OBF4 2.) K2CO3 / 1.) MeNO2, 0 deg C, 1 h 2.) CH2Cl2, MeOH/H2O, r. t. 6: tetrahydrofuran / 6 h View Scheme