1.1: 74 percent / imidazole / CH2Cl2 / 2 h / 0 °C 2.1: 80 percent / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone; H2O / CH2Cl2 / 3 h / 20 °C 3.1: 68 percent / 2-iodoxybenzoic acid / dimethylsulfoxide; CH2Cl2 / 2 h / 20 °C 4.1: NaH / tetrahydrofuran / 0 °C 4.2: 85 percent / tetrahydrofuran / 2 h 5.1: p-TsOH / methanol / 0.5 h / 20 °C 5.2: 76 percent / benzene / 1 h / 20 °C View Scheme