1: 84 percent / nBu4NF / tetrahydrofuran / 5.5 h / Ambient temperature 2: 77 percent / 80percent AcOH / 2 h / 70 °C View Scheme

1: 73 percent / mol sieves 4A, AgOTf / CH2Cl2; toluene / 4 h / -20 °C 2: 86 percent / NaOMe / methanol; CH2Cl2 / 6 h / Heating 3: 89 percent / CSA / dimethylformamide / 3 h / 40 °C 4: imidazole / dimethylformamide / 3 h / 40 - 50 °C 5: 100 percent / mol. sieves 4A, BF3*Et2O / CH2Cl2 / 3 h / Ambient temperature 6: 84 percent / nBu4NF / tetrahydrofuran / 5.5 h / Ambient temperature 7: 77 percent / 80percent AcOH / 2 h / 70 °C View Scheme

in water T=37°C; 4 h; almond emulsin;

sulfuric acid in ethanol

sulfuric acid in 1,4-dioxane T=100°C; 4 h;

hydrogenchloride in 1,4-dioxane 3 h; Heating;

Curvularia lunata 3.4381 in water T=29°C;