1: 69 percent / ethanol / 2 h / Heating 2: 21 percent / tert-butyllithium / pentane; tetrahydrofuran / 1.) -78 deg C, 24 h, 2.) room temperature 3: 85 percent / m-chloroperbenzoic acid / CHCl3 / 24 h / 0 °C 4: 93 percent / boron trifluoride etherate / diethyl ether / 3 h / Ambient temperature View Scheme

1: 69 percent / ethanol / 2 h / Heating 2: 21 percent / tert-butyllithium / pentane; tetrahydrofuran / 1.) -78 deg C, 24 h, 2.) room temperature 3: 44 percent / 550 °C / 0.1 Torr View Scheme