1: 89 percent / 4A molecular sieves; BF3*OEt2 / CH2Cl2 / 1 h / -40 °C 2: 100 percent / NaOH; water / methanol; tetrahydrofuran / 5 h / 45 °C View Scheme

1: 64 percent / pyridine / 2 h / 20 °C 2: 100 percent / 4A molecular sieves; BF3*OEt2 / CH2Cl2 / 1 h / -40 °C 3: 80 percent / TsOH*H2O / methanol; CH2Cl2 / 2 h / 20 °C 4: 75 percent / pyridine / CH2Cl2 / -20 °C 5: 89 percent / 4A molecular sieves; BF3*OEt2 / CH2Cl2 / 1 h / -40 °C 6: 100 percent / NaOH; water / methanol; tetrahydrofuran / 5 h / 45 °C View Scheme

1: 100 percent / 4A molecular sieves; BF3*OEt2 / CH2Cl2 / 1 h / -40 °C 2: 80 percent / TsOH*H2O / methanol; CH2Cl2 / 2 h / 20 °C 3: 75 percent / pyridine / CH2Cl2 / -20 °C 4: 89 percent / 4A molecular sieves; BF3*OEt2 / CH2Cl2 / 1 h / -40 °C 5: 100 percent / NaOH; water / methanol; tetrahydrofuran / 5 h / 45 °C View Scheme

in water T=37°C; 4 h; almond emulsin;

1: 93 percent / imidazole; DMAP / dimethylformamide / 20 °C 2: 58 percent / BF3*Et2O / CH2Cl2 / -40 - 20 °C 3: 95 percent / CAN / CH2Cl2; methanol / 1 h / 20 °C 4: 81 percent / NaOMe / methanol / 20 °C View Scheme

1: 94 percent / NIS; TMSOTf / CH2Cl2 / -15 - 20 °C 2: 92 percent / NaOMe / methanol / Heating 3: p-TsOH / dimethylformamide 4: 73 percent / DCC; DMAP / CH2Cl2 / 20 °C 5: 87 percent / NIS; TMSOTf / CH2Cl2 / -30 - 20 °C 6: 92 percent / HOAc / H2O / 3 h / 80 °C 7: 93 percent / imidazole; DMAP / dimethylformamide / 20 °C 8: 58 percent / BF3*Et2O / CH2Cl2 / -40 - 20 °C 9: 95 percent / CAN / CH2Cl2; methanol / 1 h / 20 °C 10: 81 percent / NaOMe / methanol / 20 °C View Scheme

furostanol glycoside 26-O-β-glucosidase-cDNA Cyclization;

β-glucosidase

1: 1.) 2 N HCl-50 percent dioxane; 2.) pyridine / 1.) reflux, 3 h 2: 0.5 percent KOH / ethanol / 0.5 h / Heating View Scheme

hydrogenchloride 3 h; Heating;