1: Et3N 2: NaN3 / dimethylformamide / Heating 3: LiAlH4 / tetrahydrofuran 4: K2CO3 5: 90 percent / NaH / dimethylformamide 6: TBAF / tetrahydrofuran 7: Et3N 8: LiI / tetrahydrofuran 9: Zn; AcOH / ethanol 10: 94 percent / NaBH4 / ethanol 11: bis(tricyclohexylphosphine)benzylideneruthenium(IV)dichlorid 12: H2 / PtO2 13: Bu3P; Py 14: NaH 15: H2O2 / H2O 16: CaCO3 / diphenyl ether / Heating 17: OsO4; NMO / H2O; tetrahydrofuran 18: Py 19: K2CO3 / methanol 20: 61 percent / KOH / methanol 21: 93 percent / HCl / H2O / Heating View Scheme