1: 1.) SeO2, t-BuOOH, 2.) LiBEt3H / 1.) 2,2,4-trimethylpentane, 4 deg C, 20 h, 2.) THF, -50 deg C -> 0 deg C 2: 88 percent / imidazole / CH2Cl2 / 1 h / Ambient temperature 3: 88 percent / MeONa, LiAlH4 / methanol; tetrahydrofuran / 1 h / Heating 4: 99 percent / TBAF / tetrahydrofuran / 16 h / Ambient temperature 5: 1.) p-TsOH, 2.) t-BuOMe, 9-acetoxyanthracene / 1.) dioxane, H2O, 75 deg C, 4 h, 2.) irradiation, 1 h View Scheme

1: 78 percent / LiAlH4, MeONa / tetrahydrofuran; methanol / 15 h / Ambient temperature 2: 98 percent / n-Bu4NF / tetrahydrofuran / 3 h / Ambient temperature 3: 1.) PPTS, 2.) t-BuOMe, 9-acetoxyanthracene / 1.) MeCN, H2O, 70 deg C, 2.5 h, 2.) irradiation, 2 h View Scheme