1.1: 95 percent / pyridine / 20 °C 2.1: 70 percent / triethyl orthoformate; p-toluenesulfonic acid / CH2Cl2 / 20 h / 20 °C 3.1: 72 percent / tetrahydrofuran; diethyl ether / 72 h / 60 °C 4.1: m-iodoxybenzoic acid; diphenyl diselenide / toluene / 22 h / Heating 4.2: 50 percent / p-toluenesulfonic acid / CH2Cl2 / 4 h / 20 °C 5.1: perchloric acid; 1,3-dibromo-5,5-dimethylhydantoin / dimethylformamide / 3 h / cooling 5.2: 75.8 percent / sodium hydroxide / CH2Cl2; methanol; H2O / 2 h / cooling 6.1: 80 percent / hydrofluoric acid / tetrahydrofuran; CH2Cl2 / 5 h / -70 - 0 °C 7.1: 100 percent / anhydrous calcium chloride; calcium oxide; iodine / methanol / 1 h / 25 - 27 °C 8.1: 180 mg / acetic acid / acetone; H2O / 3 h / Heating 9.1: 90 percent / sodium methoxide; methanol / 4 h / 25 °C View Scheme

1.1: 95 percent / pyridine / 20 °C 2.1: 70 percent / triethyl orthoformate; p-toluenesulfonic acid / CH2Cl2 / 20 h / 20 °C 3.1: 72 percent / tetrahydrofuran; diethyl ether / 72 h / 60 °C 4.1: m-iodoxybenzoic acid; diphenyl diselenide / toluene / 22 h / Heating 4.2: 50 percent / p-toluenesulfonic acid / CH2Cl2 / 4 h / 20 °C 5.1: perchloric acid; 1,3-dibromo-5,5-dimethylhydantoin / dimethylformamide / 3 h / cooling 5.2: 75.8 percent / sodium hydroxide / CH2Cl2; methanol; H2O / 2 h / cooling 6.1: 80 percent / hydrofluoric acid / tetrahydrofuran; CH2Cl2 / 5 h / -70 - 0 °C 7.1: 100 percent / anhydrous calcium chloride; calcium oxide; iodine / methanol / 1 h / 25 - 27 °C 8.1: 180 mg / acetic acid / acetone; H2O / 3 h / Heating View Scheme