1: 94 percent / TiCl4 / CH2Cl2 / 0.75 h / -85 °C 2: Et3N / CH2Cl2 / 0.5 h / 0 °C 3: NaH / tetrahydrofuran / 15 h / Ambient temperature 4: 93 percent / 7.5N aq. KOH / tetrahydrofuran; methanol / 24 h / 55 °C 5: 1) lithium, 1-dimethylaminonaphthalene / 1) THF, -85 to -35 deg C, 2) THF, -20 deg C, 1 h View Scheme

1: 94 percent / TiCl4 / CH2Cl2 / 0.75 h / -85 °C 2: Et3N / CH2Cl2 / 0.5 h / 0 °C 3: NaH / tetrahydrofuran / 15 h / Ambient temperature 4: 93 percent / 7.5N aq. KOH / tetrahydrofuran; methanol / 24 h / 55 °C 5: 1) lithium, 1-dimethylaminonaphthalene / 1) THF, -85 to -35 deg C, 2) THF, -20 deg C, 1 h View Scheme

1: 94 percent / TiCl4 / CH2Cl2 / 0.75 h / -85 °C 2: Et3N / CH2Cl2 / 0.5 h / 0 °C 3: NaH / tetrahydrofuran / 15 h / Ambient temperature 4: 93 percent / 7.5N aq. KOH / tetrahydrofuran; methanol / 24 h / 55 °C 5: 1) lithium, 1-dimethylaminonaphthalene / 1) THF, -85 to -35 deg C, 2) THF, -20 deg C, 1 h View Scheme