1: DDQ / CH2Cl2; H2O 2: DMSO, (COCl)2 / CH2Cl2 3: TsOH / benzene 4: H2 / Pd-C / ethyl acetate 5: CrO3, H2SO4 / acetone 6: 2N-HCl / tetrahydrofuran / Ambient temperature 7: (C6H11)2NMgBr / methanol / -55 °C 8: DDQ / CH2Cl2 / 1.5 h / Ambient temperature; buffer (pH 6.86) View Scheme