1: 78 percent / AcOH / diethyl ether / 1 h / Heating 2: 1.) CH3CN, 20 deg C, 20 h, 2.) MeOH 3: Zn, AcOH / 20 °C View Scheme

Multi-step reaction with 4 steps 2: 1.) LDA, 2.) 2-(phenylsulfonyl)-3-phenyloxaziridine / 1.) THF, 0 deg C, 5 h, 2.) -85 deg C to -50 deg C, 1.5 h3: 1.) NaH / DMF4: O3 / CH2Cl2 / -78 °C