potassium hydroxide in methanol; water T=20°C; 6 h;

1: imidazole / dimethylformamide 2: K2CO3 / dimethylformamide 3: dicyclohexylcarbodiimide; 4-dimethylaminopyridine / CH2Cl2 4: 6 percent / sodium acetate; O2 / acetonitrile; H2O / 1.5 h / 20 °C / Irradiation View Scheme

1: DMAP; imidazole / dimethylformamide / 18 h / 20 °C 2: o-iodoxybenzoic acid / dimethylsulfoxide / 2 h 3: 4.28 g / 2-methyl-2-butene; aq. sodium chlorite; sodium dihydrogen phosphate / 2-methyl-propan-2-ol / 1 h / 0 °C View Scheme

1: o-iodoxybenzoic acid / dimethylsulfoxide / 2 h 2: 4.28 g / 2-methyl-2-butene; aq. sodium chlorite; sodium dihydrogen phosphate / 2-methyl-propan-2-ol / 1 h / 0 °C View Scheme