1: 88 percent / imidazole / CH2Cl2 / 1 h / Ambient temperature 2: 88 percent / MeONa, LiAlH4 / methanol; tetrahydrofuran / 1 h / Heating 3: 99 percent / TBAF / tetrahydrofuran / 16 h / Ambient temperature 4: 1.) p-TsOH, 2.) t-BuOMe, 9-acetoxyanthracene / 1.) dioxane, H2O, 75 deg C, 4 h, 2.) irradiation, 1 h View Scheme