1.1: 98 percent / methanol / 13 h / 20 °C 2.1: 86 percent / citric acid; water / tetrahydrofuran / 0.5 h / 20 °C 3.1: 0.39 g / H2 / Pearlman's catalyst / ethanol / 11 h 4.1: 88 percent / NaOMe / methanol / 1.5 h / 85 °C 5.1: 90 percent / TFA / 20 °C 6.1: 69 percent / dioxane / 30 h / Heating 7.1: DDQ / CH2Cl2; methanol / 2 h / 20 °C 7.2: 89 percent / PPTS / CH2Cl2; methanol / 6 h / 45 °C View Scheme