1.1: 96.4 percent / diethyl ether / 1 h / 0 °C 2.1: 72 percent / Li-naphthalene / tetrahydrofuran / -25 °C 3.1: MnO2 / CH2Cl2 / 3 h / Heating 4.1: 33.6 mg / NaH2PO4; 2-methyl-2-butene; NaClO2 / 2-methyl-propan-2-ol; H2O / 20 °C 5.1: NEt3; 2,4,6-trichlorobenzoyl chloride / tetrahydrofuran / 6 h 5.2: 81 percent / DMAP / tetrahydrofuran; toluene / Heating 6.1: 91 percent / aq. HCl / tetrahydrofuran; H2O / 48 h / 20 °C View Scheme