1: 87 percent / PPTS / methanol 2: 96 percent / Bu4NF / tetrahydrofuran 3: 1.) BuLi / 1.) THF, -78 deg C 4: toluene / Irradiation 5: 1.) O3, 2.) Me2S / 1.) CH2Cl2, -78 deg C 6: 79 percent / NaH / tetrahydrofuran 7: 1.) HCl, 2.) DBU / 1.) CH2Cl2, MeOH, 2.) toluene, reflux 8: 76 percent / Na(Hg), Na2HPO4 / methanol / 0.17 h / -40 °C View Scheme