1: 92 percent / 1,2-dimethoxy-ethane / 0 °C 2: (S)-BINAL-H / tetrahydrofuran / -100 - -78 °C 3: 1.) m-CPBA, 2.) NH4Cl, H2O / 1.) CH2Cl2, 0 deg C 4: 72 percent / 0.1 M phosphate buffer / Baker's yeast, pH 7.0 View Scheme