1: 74.6 percent / H2 / Pb poisoned 5percent Pd/CaCO3 (Lindlar catalyst) / ethanol 2: 770 mg / conc. H2SO4 / 0.25 h / Ambient temperature 3: 1.21 g / acetic anhydride, acetic acid / Heating 4: 1.) CuI, LiI, TMSCl, 2.) n-Bu3SnH / 1.) THF, -60 deg C, 10 min, 2.) up to 0 deg C, 30 min View Scheme