1.1: magnesium / tetrahydrofuran 1.2: 79 percent / dilithium tetrachlorocuprate / tetrahydrofuran / -78 - 20 °C 2.1: 97 percent / p-toluenesulfonic acid monohydrate / ethanol / 3 h / Heating 3.1: 74 percent / Jones' CrO3 reagent / acetone / 0 - 20 °C View Scheme