1: 78 percent / SnCl4 / diethyl ether / 3 h / -80 °C 2: 90 percent / H2; NaOAc / Pd/C / tetrahydrofuran / 24 h / 20 °C 3: AcOH; water / 8 h / 50 °C 4: NaIO4 / CH2Cl2; H2O / 0.25 h 5: 5.2 g / NaBH4 / methanol / -30 - -15 °C View Scheme

hexafluoroisopropyl alcohol; scandium tris(trifluoromethanesulfonate) in dichloromethane T=-25°C; Michael addition; 18 h; Product distribution; Further Variations:CatalystsTemperatures;

1: 80 percent / SnCl4 / diethyl ether / 3 h / -85 °C 2: 92 percent / H2, AcONa / 10percent Pd/C / tetrahydrofuran / 24 h / Ambient temperature 3: 80percent aq. acetic acid / 8 h / 50 °C 4: aq. NaIO4, SiO2 / CH2Cl2 / 0.25 h 5: 1.8 g / NaBH4 / methanol / 2 h / -30 - 0 °C View Scheme