Multi-step reaction with 6 steps 1: 90 percent / n-Bu3N, PPh3 / Pd(OAc)2 / toluene / 48 h / 110 °C / 3800 Torr2: 65 percent / HCl / methanol / 12 h / 50 °C3: molecular sieve, PCC / CH2Cl2 / 2 h / Ambient temperature4: 1.) t-BuOK / 1.) THF, 20 min; 2.) THF, room temperature, 1 h5: 18 percent / N-methylmorpholine-N-oxide monohydrate, OsO4 / CH2Cl2; acetone; 2-methyl-propan-2-ol; H2O / 6 h6: Et3N / CH2Cl2 / 0.08 h / 0 °C