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