2: 84 percent / KBr, m-CPBA, 18-cr-6 / CH2Cl2 / 0.5 h / 0 °C 3: 98 percent / Mg / tetrahydrofuran View Scheme

Yield given. Multistep reaction;

2: 84 percent / KBr, m-CPBA, 18-cr-6 / CH2Cl2 / 0.5 h / 0 °C View Scheme

2: 84 percent / KBr, m-CPBA, 18-cr-6 / CH2Cl2 / 0.5 h / 0 °C 3: 98 percent / Mg / tetrahydrofuran 4: 97 percent / NaBH4 / methanol / 0.2 h / Ambient temperature 5: 98 percent / PBr3, pyridine / benzene / 3 h / Ambient temperature View Scheme