1: 65 percent / iodosobenzene, BF3-Et2O / dioxane / 12 h / Ambient temperature 2: 91 percent / sodium chlorite, 2-methyl-2-butene 3: 59 percent / 1.) NaOH/H2O/MeOH; 2.) dicyclohexylcarbodiimide in pyridine View Scheme