1.1: trimethyloxonium tetrafluoroborate / petroleum ether / 1 h / 20 °C 1.2: 63 percent / K2CO3 / CH2Cl2; H2O / 24 h 2.1: toluene / 1 h / -15 °C 2.2: 59 percent / conc. HCl / toluene; methanol / 1 h / -15 °C 3.1: 85 percent / p-TsOH*H2O / benzene / 1 h / Heating 4.1: 86 percent / DIBAH / diethyl ether; toluene / 0.25 h / -40 °C 5.1: 85 percent / 2-methyl-2-propanol; 5 percent NaH2PO4; 1M KMnO4 6.1: 80 percent / 85 percent AcOH / 0.67 h / 70 °C View Scheme