1: HCl / CH2Cl2 / 24 h / Ambient temperature 2: H2 / 5 percent Pd/C / methanol 3: 91 percent / 10 percent NaOH / 1 h / Heating 4: 15 percent / Cu(OAc)2*H2O, pyridine, lead tetraacetate / benzene / 2 h, ref., 19 h, darkness View Scheme