1: 95 percent / 3 N HCl / tetrahydrofuran / 5 h / Heating 2: 75 percent / Ag2CO3/Celite / benzene / 0.17 h / Heating 3: 1.) Et3N; 2.) DBN / 1.) CH2Cl2, in ice-bath, 30 min; 2.) benzene, reflux, 1 h 4: 1.) NBS, 1percent HClO4; 2.) AcONa / 2.) Raney-Ni / 1.) acetone, H2O, r. t., 30 min; 2.) MeOH, CH2Cl2, 30 min 5: 70 percent / H2 / Pd(OH)2/C / benzene; ethanol; cyclohexane / 2 h / Heating View Scheme