1: sulfuric acid / water / 1 h / |Reflux 2: sodium hydroxide; oxygen; catalase / water / 5 h / 25 °C / pH 7.0 / |Enzymatic reaction View Scheme

1: sulfuric acid / water / 1 h / |Reflux 2: sodium hydroxide; oxygen; catalase / water / 5 h / 25 °C / pH 7.0 / |Enzymatic reaction 3: oxygen; hydrogenchloride / water / 5 h / 130 °C / pH 5 / |Sealed tube View Scheme

sulfuric acid in water 1 h; Reflux;

1: 5-(2,2-dimethyl-1,3-dioxolan-4-yl)-2,2-dimethyltetrahydrofuro[3,2-d][1,3]dioxole With trifluoroacetic acid in water; acetic acid T=20°C; 2: acetic anhydride With pyridine Further stages.;

1: 80 percent / 30percent aq AcOH / Ambient temperature 2: 95 percent / 1,2-dichloro-ethane / Ambient temperature 3: 85 percent / 4percent aq H2SO4 / tetrahydrofuran / Heating 4: tetrahydrofuran / Ambient temperature 5: imidazole / dimethylformamide / 60 °C 6: 43 percent / n-Bu3SnH, AIBN / toluene / Heating 7: 88 percent / DIBAL-H / CH2Cl2 / -78 °C 8: 90 percent / t-BuOK / tetrahydrofuran / -78 °C 9: 94 percent / (COCl)2, DMSO, Et3N 10: 93 percent / NaN<Si(CH3)3>2 / tetrahydrofuran / Ambient temperature 11: 83 percent / (S)-BINAL-H View Scheme

acetic acid Heating;