1.1: CH3COOH / CH2Cl2 / 24 h 1.2: 90 percent / TFA / CH2Cl2 / 0.5 h 2.1: PhSH; NaH / 1,2-dimethoxy-ethane / 8 h / 20 °C 2.2: m-CPBA / CH2Cl2 / -78 °C 2.3: 64 percent / Na2CO3 / toluene / Heating 3.1: 75 percent / Ni(COD)2 / acetonitrile / 0.5 h / 20 °C 4.1: 70 percent / H2 / Crabtree's catalyst / 760.05 Torr 5.1: DMAP / tetrahydrofuran / 91 h View Scheme