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: 93 percent / SnCl4 / acetonitrile 2: 94 percent / K2CO3, MeOH / Heating 3: 81 percent / pyridine 4: 66 percent / iPr2NEt / tetrahydrofuran View Scheme

tin(IV) chloride in acetonitrile

1: With benzenesulfonamide in acetonitrile 1 h; Heating; 2: With trimethylsilyl trifluoromethanesulfonate T=20°C; 5 h; 3: With ammonium hydroxide in tetrahydrofuran; methanol T=50°C; 6 h; Further stages.;

1: 62 percent / SnCl4 / 1,2-dichloro-ethane / 20 h / 27 °C 2: 98 percent / NH3 / methanol / 12 h / 25 °C View Scheme