1: 79 percent / first generation Grubbs' catalyst / CH2Cl2 / 24 h / Heating 2: 85 percent / n-BuLi / tetrahydrofuran / -78 °C 3: PPTS / CH2Cl2 4: TBAF / tetrahydrofuran 5: Et3N; DMAP / CH2Cl2 / 0 °C 6: AgNO3 / acetonitrile 7: NaOAc / dimethylsulfoxide 8: iPr2NEt; LiCl / acetonitrile 9: PPTS / methanol 10: NaBH4 / methanol / -78 °C View Scheme