1: 1.) Ph3P / 1.) CH2Cl2, 0 deg C, 1h, 2.) -78 deg C, 40 min 2: 1.) BuLi / 1.) THF, hexane, -78 deg C, 1h, 2.) THF, hexane, HMPA, RT, 30 min 3: 95 percent / H2 / Lindlar catalyst / ethyl acetate / 0.5 h / Ambient temperature 4: 68 percent / Bu4NF / tetrahydrofuran / 1 h / Ambient temperature 5: 1.) DMSO/oxalyl chloride, 2.) NEt3 / 1.) CH2Cl2, -78 deg C, 30 min, 2.) -78 deg C to 0 deg C 6: 70percent ButOOH, 10percent aq. NaOH / tetrahydrofuran / 0.5 h / 0 °C 7: 1.) KOH, 2.) Ph3P, diethyl azodicarboxylate / 1.) MeOH, 60 deg C, 3h, 2.) benzene, RT, 13h View Scheme