potassium hydroxide; 18-crown-6 ether; oxygen in benzene 24 h;

methanesulfonic acid in dichloromethane Yield given;

1: CH3SO3H / CH2Cl2 2: 87 percent / OsO4, N-methylmorpholine N-oxide dihydrate / tetrahydrofuran; H2O / 144 h / Ambient temperature 3: 97 percent / CH3SO3H / CH2Cl2 View Scheme

1: CH3SO3H / CH2Cl2 2: 87 percent / OsO4, N-methylmorpholine N-oxide dihydrate / tetrahydrofuran; H2O / 144 h / Ambient temperature 3: 97 percent / CH3SO3H / CH2Cl2 4: 96 percent / hexamethyldisilazane / CH2Cl2 / Ambient temperature View Scheme

1: CH3SO3H / CH2Cl2 2: 87 percent / OsO4, N-methylmorpholine N-oxide dihydrate / tetrahydrofuran; H2O / 144 h / Ambient temperature 3: 97 percent / CH3SO3H / CH2Cl2 4: 96 percent / hexamethyldisilazane / CH2Cl2 / Ambient temperature 5: 61 percent / 99percent m-chloroperoxybenzoic acid / CH2Cl2 / 0.58 h / 0 °C View Scheme

1: CH3SO3H / CH2Cl2 2: 87 percent / OsO4, N-methylmorpholine N-oxide dihydrate / tetrahydrofuran; H2O / 144 h / Ambient temperature 3: 97 percent / CH3SO3H / CH2Cl2 4: 96 percent / hexamethyldisilazane / CH2Cl2 / Ambient temperature 5: 61 percent / 99percent m-chloroperoxybenzoic acid / CH2Cl2 / 0.58 h / 0 °C 6: 92 percent / hexamethyldisilazane / pyridine / 0.75 h / Ambient temperature View Scheme