1.1: 89 percent / ethanol; H2O / 12 h / 20 °C 2.1: Zn / tetrahydrofuran / 0.17 h / 50 °C / ultrasonic irradiation 2.2: 69 percent / tetrahydrofuran / 5.5 h / 50 °C / ultrasonic irradiation 3.1: 84 percent / p-toluenesulfonic acid / CH2Cl2 / 2 h / 20 °C View Scheme

1.1: 97 percent / aq. HCl / methanol / 1 h / 20 °C 2.1: 75 percent / pyridine / 12 h / -17 °C 3.1: 89 percent / ethanol; H2O / 12 h / 20 °C 4.1: Zn / tetrahydrofuran / 0.17 h / 50 °C / ultrasonic irradiation 4.2: 69 percent / tetrahydrofuran / 5.5 h / 50 °C / ultrasonic irradiation 5.1: 84 percent / p-toluenesulfonic acid / CH2Cl2 / 2 h / 20 °C View Scheme

1.1: 90 percent / potassium carbonate / methanol 2.1: lithium diisopropylamide / tetrahydrofuran / -78 °C 2.2: tetrahydrofuran / -78 °C 3.1: TFA / CH2Cl2 / 10 h View Scheme

1.1: titanium(IV) isopropylate; (R)-2,2'-dihydroxy-1,1'-binaphthyl; trifluoroacetic acid / dichloromethane / -78 °C / |Molecular sieve 1.2: 120 h / -25 °C 2.1: ozone; oxygen / dichloromethane / 1 h / -78 °C 2.2: 20 °C 3.1: sodium carbonate / methanol / 12 h View Scheme

1.1: ozone; oxygen / dichloromethane / 1 h / -78 °C 1.2: 20 °C 2.1: sodium carbonate / methanol / 12 h View Scheme

potassium carbonate in acetone T=20°C; 20 h;