1: 98 percent / H2 / Pd/C / aq. ethanol / 1.5 h 2: 88 percent / PyBroP; 1-hydroxy-7-azabenzotriazole; DIPEA / CH2Cl2 / 48 h / 20 °C 3: 76 percent / tin(II) trifluoromethanesulfonate / acetone / 48 h / 40 °C 4: 90 percent / AIBN; Bu3SnH / toluene / 16 h / Heating View Scheme

hydrogen; palladium on activated charcoal in ethanol 1.5 h;