sulfuric acid in ethanol T=20°C; 4 h;

BrettPhosAuNTf2; trifluoroacetic acid in dichloromethane T=20°C; 24 h;

hydrogenchloride in methanol 2 h; Heating;

1: 37 percent / Na2WO4 hydrate, 36percent aq. H2O2 / methanol / 3 h / a) 0 deg C, 2 h, b) RT, 1 h 2: 48 h / 70 °C 3: 50 percent / 1,3,5-trimethyl-benzene / 4 h / Heating View Scheme

1: 98 percent / benzene / a.) 0 deg C, 15 min, b.) r. t., overnight, c.) 19 h, reflux 2: 72 percent / p-TsOH / benzene / 1 h / Heating 3: 62 percent / K2CO3 / ethanol / 15 h / Heating 4: KtBuO / tetrahydrofuran / 0.5 h / 0 °C 5: 69 percent / tetrahydrofuran / 0.5 h / Ambient temperature; pH 4 (aq. buffer solution citric acid - sodium acetate) 6: 65 percent / aq. 50percent HOAc / 15 h / Ambient temperature View Scheme

1: 69 percent / tetrahydrofuran / 0.5 h / Ambient temperature; pH 4 (aq. buffer solution citric acid - sodium acetate) 2: 65 percent / aq. 50percent HOAc / 15 h / Ambient temperature View Scheme

1: 62 percent / K2CO3 / ethanol / 15 h / Heating 2: KtBuO / tetrahydrofuran / 0.5 h / 0 °C 3: 69 percent / tetrahydrofuran / 0.5 h / Ambient temperature; pH 4 (aq. buffer solution citric acid - sodium acetate) 4: 65 percent / aq. 50percent HOAc / 15 h / Ambient temperature View Scheme

1: KtBuO / tetrahydrofuran / 0.5 h / 0 °C 2: 69 percent / tetrahydrofuran / 0.5 h / Ambient temperature; pH 4 (aq. buffer solution citric acid - sodium acetate) 3: 65 percent / aq. 50percent HOAc / 15 h / Ambient temperature View Scheme

1: 72 percent / p-TsOH / benzene / 1 h / Heating 2: 62 percent / K2CO3 / ethanol / 15 h / Heating 3: KtBuO / tetrahydrofuran / 0.5 h / 0 °C 4: 69 percent / tetrahydrofuran / 0.5 h / Ambient temperature; pH 4 (aq. buffer solution citric acid - sodium acetate) 5: 65 percent / aq. 50percent HOAc / 15 h / Ambient temperature View Scheme

1: 90 percent / potassium carbonate / ethanol; H2O / 0.5 h / Heating 2: 1) m-(chloroperoxy)benzoic acid, 2) triethylamine, acetic anhydride / 1) diethyl ether/dichloromethane, 0 to 20 deg C, 2 h, 2) CH2Cl2, 0 deg C, 30 min 3: 90 percent / 10percent aq. sulfuric acid / ethanol / 4 h / 20 °C View Scheme