1: 70 percent / p-toluenesulfonic acid monohydrate / ethanol / 29 h / 20 °C 2: 99 percent / pyridine; H2 / Lindlar catalyst / pentane / 15 h / 20 °C 3: formic acid / CH2Cl2 / 0.17 h / 20 °C View Scheme

1: 89 percent / K2CO3 / tetrahydrofuran; 2-methyl-propan-2-ol / Ambient temperature 3: 1.) CF3COOH; 2.) H2O / 1.) benzene, room temp., 1 h; 2.) room temp., 48 h View Scheme