Multi-step reaction with 2 steps 1: 80 percent / m-chloroperbenzoic acid / CH2Cl2 2: 70 percent / lithium diisopropylamide, hexamethylphosphortriamide / tetrahydrofuran / -78 °C  

Multi-step reaction with 2 steps 1: 80 percent / m-chloroperbenzoic acid / CH2Cl2 2: 68 percent / lithium diisopropylamide, hexamethylphosphortriamide / tetrahydrofuran / -78 °C  

Multi-step reaction with 2 steps 1: 80 percent / m-chloroperbenzoic acid / CH2Cl2 2: 65 percent / lithium diisopropylamide, hexamethylphosphortriamide / tetrahydrofuran / -78 °C  

Multi-step reaction with 3 steps 1: 80 percent / m-chloroperbenzoic acid / CH2Cl2 2: 68 percent / lithium diisopropylamide, hexamethylphosphortriamide / tetrahydrofuran / -78 °C3: tetrafluoroboric acid (50percent) / CH2Cl2; H2O / 7 h / Heating