steroidal saponin-β-glucosidase from Aspergillus flavus in aq. buffer T=50°C; pH=5; Enzymatic reaction;

sodium methylate in methanol; dichloromethane T=20°C;

1: With acetic acid T=70°C; 2 h; 2: With methanol; sodium methylate in dichloromethane T=40°C; Further stages.;

acetic acid T=70°C; 2 h;

sulfuric acid in ethanol; water T=70°C; 3 h;

1: 85 percent / 4 Angstroem molecular sieves; BF3*Et2O / CH2Cl2 / 3 h / 20 °C 2: 95 percent / HBr; HOAc / CH2Cl2 / 3 h / 0 - 20 °C 3: 68 percent / CdCO3 / acetonitrile / 2 h / 65 °C 4: 100 percent / MeONa / methanol; CH2Cl2 / 20 °C View Scheme

1: 85 percent / 4 Angstroem molecular sieves; BF3*Et2O / CH2Cl2 / 3 h / 20 °C 2: 95 percent / HBr; HOAc / CH2Cl2 / 3 h / 0 - 20 °C 3: 68 percent / CdCO3 / acetonitrile / 2 h / 65 °C 4: 100 percent / MeONa / methanol; CH2Cl2 / 20 °C View Scheme

1: 68 percent / CdCO3 / acetonitrile / 2 h / 65 °C 2: 100 percent / MeONa / methanol; CH2Cl2 / 20 °C View Scheme

1: 95 percent / HBr; HOAc / CH2Cl2 / 3 h / 0 - 20 °C 2: 68 percent / CdCO3 / acetonitrile / 2 h / 65 °C 3: 100 percent / MeONa / methanol; CH2Cl2 / 20 °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