1: Et2AlCl / CH2Cl2 / 2 h / -50 °C 2: Dess-Martin periodinane; NaHCO3 / CH2Cl2 3: KOtBu / tetrahydrofuran 4: 84 percent / Grubbs' 2nd generation catalyst / CH2Cl2 / 12 h / 40 °C 5: DIBAL-H / CH2Cl2 / -78 °C 6: KOtBu / tetrahydrofuran 7: HCl / tetrahydrofuran / 48 h View Scheme

1: Dess-Martin periodinane; NaHCO3 / CH2Cl2 2: KOtBu / tetrahydrofuran 3: 84 percent / Grubbs' 2nd generation catalyst / CH2Cl2 / 12 h / 40 °C 4: DIBAL-H / CH2Cl2 / -78 °C 5: KOtBu / tetrahydrofuran 6: HCl / tetrahydrofuran / 48 h View Scheme

1: imidazole / dimethylformamide 2: Et2AlCl / CH2Cl2 / 2 h / -50 °C 3: Dess-Martin periodinane; NaHCO3 / CH2Cl2 4: KOtBu / tetrahydrofuran 5: 84 percent / Grubbs' 2nd generation catalyst / CH2Cl2 / 12 h / 40 °C 6: DIBAL-H / CH2Cl2 / -78 °C 7: KOtBu / tetrahydrofuran 8: HCl / tetrahydrofuran / 48 h View Scheme

1: KOtBu / tetrahydrofuran 2: K2CO3 / methanol 3: imidazole / dimethylformamide 4: 84 percent / Grubbs' 2nd generation catalyst / CH2Cl2 / 12 h / 40 °C 5: DIBAL-H / CH2Cl2 / -78 °C 6: KOtBu / tetrahydrofuran 7: HCl / tetrahydrofuran / 48 h View Scheme

1: K2CO3 / methanol 2: imidazole / dimethylformamide 3: 84 percent / Grubbs' 2nd generation catalyst / CH2Cl2 / 12 h / 40 °C 4: DIBAL-H / CH2Cl2 / -78 °C 5: KOtBu / tetrahydrofuran 6: HCl / tetrahydrofuran / 48 h View Scheme

1.1: D-(-)-diethyl tartrate; Ti(O-isoiPr)4; BuOOH / CH2Cl2 / 20 h / -20 °C 2.1: CuCN / tetrahydrofuran; diethyl ether / 1 h / -30 °C 2.2: tetrahydrofuran; diethyl ether / 8 h / -12 °C 3.1: pyridinium p-toluenesulfonate / CHCl3 / 12 h / 20 °C 4.1: O3 / CH2Cl2 / -78 °C 4.2: Ph3P / CH2Cl2 / 12 h / 20 °C 5.1: benzene / 7 h / 65 °C 6.1: DIBAL-H / toluene; hexane / 1 h / -78 °C 7.1: PCC; NaOAc; molecular sieves 4 Angstroem / CH2Cl2 / 1 h / 0 °C 8.1: BuLi / tetrahydrofuran; hexane / 0.25 h / 0 °C 8.2: tetrahydrofuran; hexane / 3 h / -78 - 0 °C 9.1: tetrabutylammonium fluoride / tetrahydrofuran / 2 h / 20 °C 10.1: Dess-Martin reagent / CH2Cl2 / 1 h / 0 °C 11.1: Ni(cod)2; PPh3; i-Bu2-ALAC / toluene / 2 h / 0 °C 12.1: imidazole / dimethylformamide / 7 h / 20 °C 13.1: O3; O2 / CH2Cl2 / -78 °C 13.2: PPh3 / CH2Cl2 / 12 h / 20 °C 14.1: potassium tert-butoxide / tetrahydrofuran / 1 h / 20 °C 14.2: tetrahydrofuran / 0.25 h 15.1: methanol; diethyl ether / 0 °C 16.1: tetrabutylammonium fluoride / tetrahydrofuran / 3 h / 20 °C 17.1: DMAP; pyridine / CH2Cl2 / 2 h / 20 °C 18.1: Dowex50W / methanol / 0.5 h / 50 °C 19.1: Et3N; DMAP / CH2Cl2 / 36 h / 20 °C 20.1: pyridinium p-toluenesulfonate / CH2Cl2 / 12 h / 20 °C 21.1: tetrabutylammonium fluoride / tetrahydrofuran / 16 h / 0 °C 22.1: PCC; 4 Angstroem molecular sieves / CH2Cl2 / 1 h / 0 °C 23.1: NaH / tetrahydrofuran / 0.08 h / 20 °C 23.2: tetrahydrofuran / 1 h 24.1: LiAlH4; (S)-binaphthol / tetrahydrofuran; ethanol / 1 h / -78 °C 25.1: aq. AcOH / tetrahydrofuran / 2.5 h / 40 °C 26.1: 1.0 M aq. NaOH / methanol; tetrahydrofuran / 2 h / 20 °C View Scheme

2: acid hydrolysis 3: Pb(OAc)4 4: over Li-acetylide 5: 49 percent / Swern oxidation 6: Zn(BH4)2 / diethyl ether 7: LiAlH4 9: acid, H2O 10: NH2OH*HCl, pyridine 11: 5percent sodium hypochlorite, Et3N 12: H2, boric acid / W-2 Raney nickel 13: MsCl, DMAP 15: 97 percent / PPTS / methanol 16: CrO3, H2SO4 17: L-selectride 18: 75 percent / Na, liq. NH3 View Scheme

1: NH2OH*HCl, pyridine 2: 5percent sodium hypochlorite, Et3N 3: H2, boric acid / W-2 Raney nickel 4: MsCl, DMAP 6: 97 percent / PPTS / methanol 7: CrO3, H2SO4 8: L-selectride 9: 75 percent / Na, liq. NH3 View Scheme

1: Pb(OAc)4 2: over Li-acetylide 3: 49 percent / Swern oxidation 4: Zn(BH4)2 / diethyl ether 5: LiAlH4 7: acid, H2O 8: NH2OH*HCl, pyridine 9: 5percent sodium hypochlorite, Et3N 10: H2, boric acid / W-2 Raney nickel 11: MsCl, DMAP 13: 97 percent / PPTS / methanol 14: CrO3, H2SO4 15: L-selectride 16: 75 percent / Na, liq. NH3 View Scheme

1: 5percent sodium hypochlorite, Et3N 2: H2, boric acid / W-2 Raney nickel 3: MsCl, DMAP 5: 97 percent / PPTS / methanol 6: CrO3, H2SO4 7: L-selectride 8: 75 percent / Na, liq. NH3 View Scheme