1: [(3aR,5S,6aR)-2,2-dimethyltetrhydrofuro[2,3-d][1,3]dioxol-5-yl]methyl benzoate With acetic acid 2 h; Heating; 2: acetic anhydride With pyridine; 4-(N,N-dimethlyamino)pyridine T=20°C; Further stages.;

1: 76 percent / H2SO4 / H2O; dioxane / 4 h / 70 - 80 °C 2: 49.8 percent / (diethylamino)sulfur trifluoride / CH2Cl2 / 0 - 25 °C 3: 20 percent / TMSOTf / 1,2-dichloro-ethane / Heating 4: H2, NH4OH / 10percent Pd/C / methanol; tetrahydrofuran / 3 h / 2585.7 Torr / Ambient temperature 5: methanolic ammonia View Scheme