1: 95 percent / dimethylcarbamyl chloride / CH2Cl2 / 120 h / Ambient temperature 2: 2.) 5N aq. HCl / 1.) Et2O, 1 night, 2.) Et2O, 12 h 3: 96 percent / NaBH4, NaOH / methanol / 12 h 4: 92 percent / 85percent H2SO4 / 2 h / 110 - 120 °C 5: 1.) O3, 2.) 35percent aq. H2O2, 5percent aq. NaOH / 1.) CH2Cl2, RT, 24 h, 2.) EtOH, reflux, 24 h View Scheme