methanol; sodium methylate T=25°C; 4 h;

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: 80 percent / hydrofluoric acid / tetrahydrofuran; CH2Cl2 / 5 h / -70 - 0 °C 2: 100 percent / anhydrous calcium chloride; calcium oxide; iodine / methanol / 1 h / 25 - 27 °C 3: 180 mg / acetic acid / acetone; H2O / 3 h / Heating 4: 90 percent / sodium methoxide; methanol / 4 h / 25 °C View Scheme

1.1: m-iodoxybenzoic acid; diphenyl diselenide / toluene / 22 h / Heating 1.2: 50 percent / p-toluenesulfonic acid / CH2Cl2 / 4 h / 20 °C 2.1: perchloric acid; 1,3-dibromo-5,5-dimethylhydantoin / dimethylformamide / 3 h / cooling 2.2: 75.8 percent / sodium hydroxide / CH2Cl2; methanol; H2O / 2 h / cooling 3.1: 80 percent / hydrofluoric acid / tetrahydrofuran; CH2Cl2 / 5 h / -70 - 0 °C 4.1: 100 percent / anhydrous calcium chloride; calcium oxide; iodine / methanol / 1 h / 25 - 27 °C 5.1: 180 mg / acetic acid / acetone; H2O / 3 h / Heating 6.1: 90 percent / sodium methoxide; methanol / 4 h / 25 °C View Scheme

1.1: 72 percent / tetrahydrofuran; diethyl ether / 72 h / 60 °C 2.1: m-iodoxybenzoic acid; diphenyl diselenide / toluene / 22 h / Heating 2.2: 50 percent / p-toluenesulfonic acid / CH2Cl2 / 4 h / 20 °C 3.1: perchloric acid; 1,3-dibromo-5,5-dimethylhydantoin / dimethylformamide / 3 h / cooling 3.2: 75.8 percent / sodium hydroxide / CH2Cl2; methanol; H2O / 2 h / cooling 4.1: 80 percent / hydrofluoric acid / tetrahydrofuran; CH2Cl2 / 5 h / -70 - 0 °C 5.1: 100 percent / anhydrous calcium chloride; calcium oxide; iodine / methanol / 1 h / 25 - 27 °C 6.1: 180 mg / acetic acid / acetone; H2O / 3 h / Heating 7.1: 90 percent / sodium methoxide; methanol / 4 h / 25 °C View Scheme

1: 180 mg / acetic acid / acetone; H2O / 3 h / Heating 2: 90 percent / sodium methoxide; methanol / 4 h / 25 °C View Scheme

1.1: perchloric acid; 1,3-dibromo-5,5-dimethylhydantoin / dimethylformamide / 3 h / cooling 1.2: 75.8 percent / sodium hydroxide / CH2Cl2; methanol; H2O / 2 h / cooling 2.1: 80 percent / hydrofluoric acid / tetrahydrofuran; CH2Cl2 / 5 h / -70 - 0 °C 3.1: 100 percent / anhydrous calcium chloride; calcium oxide; iodine / methanol / 1 h / 25 - 27 °C 4.1: 180 mg / acetic acid / acetone; H2O / 3 h / Heating 5.1: 90 percent / sodium methoxide; methanol / 4 h / 25 °C View Scheme

1.1: 91.7 percent / hydrogen peroxide; sodium hydroxide / methanol / 2 h / 20 °C 2.1: 95 percent / pyridine / 20 °C 3.1: 70 percent / triethyl orthoformate; p-toluenesulfonic acid / CH2Cl2 / 20 h / 20 °C 4.1: 72 percent / tetrahydrofuran; diethyl ether / 72 h / 60 °C 5.1: m-iodoxybenzoic acid; diphenyl diselenide / toluene / 22 h / Heating 5.2: 50 percent / p-toluenesulfonic acid / CH2Cl2 / 4 h / 20 °C 6.1: perchloric acid; 1,3-dibromo-5,5-dimethylhydantoin / dimethylformamide / 3 h / cooling 6.2: 75.8 percent / sodium hydroxide / CH2Cl2; methanol; H2O / 2 h / cooling 7.1: 80 percent / hydrofluoric acid / tetrahydrofuran; CH2Cl2 / 5 h / -70 - 0 °C 8.1: 100 percent / anhydrous calcium chloride; calcium oxide; iodine / methanol / 1 h / 25 - 27 °C 9.1: 180 mg / acetic acid / acetone; H2O / 3 h / Heating 10.1: 90 percent / sodium methoxide; methanol / 4 h / 25 °C View Scheme

1.1: pyridine; ammonium chloride / 125 - 135 °C 1.2: acetic acid; chromium trioxide / H2O; 1,2-dichloro-ethane / 1 h / 20 °C 1.3: 57 percent / aluminium oxide / benzene / 2 h 2.1: 91.7 percent / hydrogen peroxide; sodium hydroxide / methanol / 2 h / 20 °C 3.1: 95 percent / pyridine / 20 °C 4.1: 70 percent / triethyl orthoformate; p-toluenesulfonic acid / CH2Cl2 / 20 h / 20 °C 5.1: 72 percent / tetrahydrofuran; diethyl ether / 72 h / 60 °C 6.1: m-iodoxybenzoic acid; diphenyl diselenide / toluene / 22 h / Heating 6.2: 50 percent / p-toluenesulfonic acid / CH2Cl2 / 4 h / 20 °C 7.1: perchloric acid; 1,3-dibromo-5,5-dimethylhydantoin / dimethylformamide / 3 h / cooling 7.2: 75.8 percent / sodium hydroxide / CH2Cl2; methanol; H2O / 2 h / cooling 8.1: 80 percent / hydrofluoric acid / tetrahydrofuran; CH2Cl2 / 5 h / -70 - 0 °C 9.1: 100 percent / anhydrous calcium chloride; calcium oxide; iodine / methanol / 1 h / 25 - 27 °C 10.1: 180 mg / acetic acid / acetone; H2O / 3 h / Heating 11.1: 90 percent / sodium methoxide; methanol / 4 h / 25 °C View Scheme

1.1: 70 percent / triethyl orthoformate; p-toluenesulfonic acid / CH2Cl2 / 20 h / 20 °C 2.1: 72 percent / tetrahydrofuran; diethyl ether / 72 h / 60 °C 3.1: m-iodoxybenzoic acid; diphenyl diselenide / toluene / 22 h / Heating 3.2: 50 percent / p-toluenesulfonic acid / CH2Cl2 / 4 h / 20 °C 4.1: perchloric acid; 1,3-dibromo-5,5-dimethylhydantoin / dimethylformamide / 3 h / cooling 4.2: 75.8 percent / sodium hydroxide / CH2Cl2; methanol; H2O / 2 h / cooling 5.1: 80 percent / hydrofluoric acid / tetrahydrofuran; CH2Cl2 / 5 h / -70 - 0 °C 6.1: 100 percent / anhydrous calcium chloride; calcium oxide; iodine / methanol / 1 h / 25 - 27 °C 7.1: 180 mg / acetic acid / acetone; H2O / 3 h / Heating 8.1: 90 percent / sodium methoxide; methanol / 4 h / 25 °C View Scheme