1: 1.) O3, NaHCO3, 2.) Me2S / 1.) CH2Cl2, MeOH, -70 deg C, 6 h, 2.) CH2Cl2, MeOH, RT, 15 h 2: 1.) n-BuLi / 1.) THF, hexane, 0 deg C, 2.) THF, hexane, 0 deg C, 40 min 3: 76.2 percent / H2CrO4 / acetone; H2O / 0 °C 4: 87 percent / H2 / 5percent Pd/C / ethyl acetate / 2 h / 2585.7 Torr View Scheme

Multi-step reaction with 2 steps 1: 1.) O3, NaHCO3, 2.) Me2S / 1.) CH2Cl2, MeOH, -70 deg C, 6 h, 2.) CH2Cl2, MeOH, RT, 15 h2: 1.) n-BuLi / 1.) THF, hexane, 0 deg C, 2.) THF, hexane, 0 deg C, 40 min  

Multi-step reaction with 3 steps 1: 1.) O3, NaHCO3, 2.) Me2S / 1.) CH2Cl2, MeOH, -70 deg C, 6 h, 2.) CH2Cl2, MeOH, RT, 15 h2: 1.) n-BuLi / 1.) THF, hexane, 0 deg C, 2.) THF, hexane, 0 deg C, 40 min3: 76.2 percent / H2CrO4 / acetone; H2O / 0 °C  

Stage #1: With  pyridine; ozone in  methanol; dichloromethane T=-78°C; Stage #2: With  dimethylsulfide in  methanol; dichloromethane T=-78 - 20°C; 18 h;  Further stages.;