potassium carbonate in N,N-dimethyl-formamide T=60°C;

potassium carbonate in tetrahydrofuran T=20°C;

perchloric acid on silica gel in acetonitrile T=50°C; 0.5 h; chemoselective reaction;

tetrabutyl ammonium fluoride in tetrahydrofuran T=20°C; 4 h;

1: succinic acid anhydride; C30H47O3Pol With 4-(N,N-dimethlyamino)pyridine; triethylamine in dichloromethane; N,N-dimethyl-formamide T=20°C; 24 h; 2: With trifluoroacetic acid in dichloromethane 3: benzyl chloride With potassium carbonate in N,N-dimethyl-formamide T=55°C; 4 h;

in 1,4-dioxane; toluene T=60°C; 2 h;

sodium hydroxide in tetrahydrofuran; methanol T=20°C;

1: triethylamine / dichloromethane / 12 h / 24 °C 2: triethylamine / dichloromethane / 12 h / 24 °C 3: lithium; ammonia 4: potassium carbonate / N,N-dimethyl-formamide / 19 h / 20 °C View Scheme

1: triethylamine / dichloromethane / 12 h / 24 °C 2: lithium; ammonia 3: potassium carbonate / N,N-dimethyl-formamide / 19 h / 20 °C View Scheme

1: 94 percent / 4 Angstroem molecular sieves; TMSOTf / CH2Cl2 / 0.33 h / 20 °C 2: 97 percent / NaOMe / CH2Cl2; methanol / 2 h / 20 °C 3: 89 percent / TsOH / acetone / 0 - 20 °C 4: 79 percent / 4 Angstroem molecular sieves; BF3*Et2O / CH2Cl2 / 2 h / -78 °C 5: 98 percent / TsOH / CH2Cl2; methanol / 20 °C 6: H2 / Pd-C / ethyl acetate / 3 h / Heating 7: 35 mg / NaOMe / CH2Cl2; methanol / 2 h / 20 °C View Scheme