1: (3aR,5R,6aR)-6-Allyloxy-5-(2,2-dimethyl-[1,3]dioxolan-4-yl)-2,2-dimethyl-tetrahydro-furo[2,3-d][1,3]dioxole With amberlite IR-120 H in methanol 2: acetic anhydride With 4-(N,N-dimethlyamino)pyridine in pyridine

sodium acetate 0.416667 h; Heating;

1: H2SO4 / H2O / Heating 2: NaOAc View Scheme

1: NaH / dimethylformamide / 20 °C 2: H2SO4 / H2O / Heating 3: NaOAc View Scheme

sodium acetate

sulfuric acid; sodium acetate 1.) reflux, 3 h, 2.) reflux, 1.5 h; Yield given. Multistep reaction;

sodium acetate Heating; Yield given;

boron trifluoride diethyl etherate in dichloromethane

1: 100 percent / α,α-dichloromethyl methyl ether; ZnCl2*Et2O / CH2Cl2 / 1 h / 20 °C 2: 72 percent / silver carbonate; molecular sieves (4 Angstroem) / 1,2-dichloro-ethane / 20 °C 3: 94 percent / sodium methoxide / methanol / 2 h / 20 °C 4: 86 percent / pyridine / 0 - 20 °C 5: 92 percent / pyridine / 0 - 20 °C 6: 79 percent / AcOH / dioxane / 6 h / 110 °C 7: 79 percent / DCC; DMAP; DMAP*HCl / CH2Cl2 / Heating 8: 66 percent / selenium dioxide; AcOH / dioxane / 3 h / 80 °C 9: 73 percent / boron trifluoride diethyl etherate / CH2Cl2 / 5 h / -20 °C 10: 49 percent / methylamine / CH2Cl2; methanol / 9 h / -20 °C 11: 44 percent / 1,4-cyclohexadiene / Pd/C / dimethylformamide; ethanol / 10 h / 40 °C View Scheme