1.1: NaHMDS / tetrahydrofuran; toluene / 0.5 h / 0 °C 1.2: 89 percent / tetrahydrofuran; toluene; hexamethylphosphoric acid triamide / 6 h / 0 - 20 °C 2.1: 96 percent / p-TsOH*H2O / methanol / 8 h / 20 °C 3.1: mCPBA / 1,2-dichloro-ethane / 0.25 h / 0 °C 4.1: 720 mg / toluene / 0.5 h / Heating 5.1: 95 percent / Dess-Martin periodinane / 1,2-dichloro-ethane / 0.25 h / 20 °C 6.1: 85 percent / CrCl2 / tetrahydrofuran / 8 h / 20 °C 7.1: 66 percent / Et3N; CuI / Pd(PPh3)4 / benzene; tetrahydrofuran / 2 h / 20 °C 8.1: H2 / Rh(PPh3)3Cl / benzene / 8 h 9.1: 1.0 mg / Me2S; BF3*Et2O / 0.08 h / 0 °C View Scheme

1.1: 91 percent / NaOH / methanol / 8 h / 20 °C 2.1: 94 percent / i-Pr2NEt / CH2Cl2 / 12 h 3.1: n-BuLi / tetrahydrofuran; hexane / 1 h / -10 - 0 °C 3.2: 70 percent / tetrahydrofuran; hexane / 3 h / 0 - 20 °C 4.1: 94 percent / Na / liquid ammonia; tetrahydrofuran; 2-methyl-propan-2-ol / 8 h / -40 °C 5.1: 96 percent / aq. AcOH / 1 h / 60 °C 6.1: 95 percent / DMAP; Et3N / CH2Cl2 / 12 h 7.1: Et3N / CH2Cl2 / 0.17 h / -10 °C 8.1: 77 mg / TBAF / tetrahydrofuran / 10 h / 0 - 20 °C 9.1: n-BuLi / tetrahydrofuran; hexane / 0.5 h / -78 °C 9.2: BF3*Et2O / tetrahydrofuran; hexane / 1 h 10.1: 69 mg / TBAF / tetrahydrofuran / 5 h / 0 - 20 °C 11.1: Et3N / CH2Cl2 / 0.17 h / -10 °C 12.1: AD mix α; methanesulfonamide / 2-methyl-propan-2-ol; H2O / 48 h / 0 °C 13.1: 18 mg / Triton B / methanol / 24 h 14.1: 66 percent / Et3N; CuI / Pd(PPh3)4 / benzene; tetrahydrofuran / 2 h / 20 °C 15.1: H2 / Rh(PPh3)3Cl / benzene / 8 h 16.1: 1.0 mg / Me2S; BF3*Et2O / 0.08 h / 0 °C View Scheme

1: 95 percent / Dess-Martin periodinane / 1,2-dichloro-ethane / 0.25 h / 20 °C 2: 85 percent / CrCl2 / tetrahydrofuran / 8 h / 20 °C 3: 66 percent / Et3N; CuI / Pd(PPh3)4 / benzene; tetrahydrofuran / 2 h / 20 °C 4: H2 / Rh(PPh3)3Cl / benzene / 8 h 5: 1.0 mg / Me2S; BF3*Et2O / 0.08 h / 0 °C View Scheme

1: 85 percent / CrCl2 / tetrahydrofuran / 8 h / 20 °C 2: 66 percent / Et3N; CuI / Pd(PPh3)4 / benzene; tetrahydrofuran / 2 h / 20 °C 3: H2 / Rh(PPh3)3Cl / benzene / 8 h 4: 1.0 mg / Me2S; BF3*Et2O / 0.08 h / 0 °C View Scheme

1: 66 percent / Et3N; CuI / Pd(PPh3)4 / benzene; tetrahydrofuran / 2 h / 20 °C 2: H2 / Rh(PPh3)3Cl / benzene / 8 h 3: 1.0 mg / Me2S; BF3*Et2O / 0.08 h / 0 °C View Scheme

1: mCPBA / 1,2-dichloro-ethane / 0.25 h / 0 °C 2: 720 mg / toluene / 0.5 h / Heating 3: 95 percent / Dess-Martin periodinane / 1,2-dichloro-ethane / 0.25 h / 20 °C 4: 85 percent / CrCl2 / tetrahydrofuran / 8 h / 20 °C 5: 66 percent / Et3N; CuI / Pd(PPh3)4 / benzene; tetrahydrofuran / 2 h / 20 °C 6: H2 / Rh(PPh3)3Cl / benzene / 8 h 7: 1.0 mg / Me2S; BF3*Et2O / 0.08 h / 0 °C View Scheme

1.1: n-BuLi / tetrahydrofuran; hexane / 0.5 h / -78 °C 1.2: BF3*Et2O / tetrahydrofuran; hexane / 1 h 2.1: 69 mg / TBAF / tetrahydrofuran / 5 h / 0 - 20 °C 3.1: Et3N / CH2Cl2 / 0.17 h / -10 °C 4.1: AD mix α; methanesulfonamide / 2-methyl-propan-2-ol; H2O / 48 h / 0 °C 5.1: 18 mg / Triton B / methanol / 24 h 6.1: 66 percent / Et3N; CuI / Pd(PPh3)4 / benzene; tetrahydrofuran / 2 h / 20 °C 7.1: H2 / Rh(PPh3)3Cl / benzene / 8 h 8.1: 1.0 mg / Me2S; BF3*Et2O / 0.08 h / 0 °C View Scheme

1.1: 95 percent / DMAP; Et3N / CH2Cl2 / 12 h 2.1: Et3N / CH2Cl2 / 0.17 h / -10 °C 3.1: 77 mg / TBAF / tetrahydrofuran / 10 h / 0 - 20 °C 4.1: n-BuLi / tetrahydrofuran; hexane / 0.5 h / -78 °C 4.2: BF3*Et2O / tetrahydrofuran; hexane / 1 h 5.1: 69 mg / TBAF / tetrahydrofuran / 5 h / 0 - 20 °C 6.1: Et3N / CH2Cl2 / 0.17 h / -10 °C 7.1: AD mix α; methanesulfonamide / 2-methyl-propan-2-ol; H2O / 48 h / 0 °C 8.1: 18 mg / Triton B / methanol / 24 h 9.1: 66 percent / Et3N; CuI / Pd(PPh3)4 / benzene; tetrahydrofuran / 2 h / 20 °C 10.1: H2 / Rh(PPh3)3Cl / benzene / 8 h 11.1: 1.0 mg / Me2S; BF3*Et2O / 0.08 h / 0 °C View Scheme

1: Et3N / CH2Cl2 / 0.17 h / -10 °C 2: AD mix α; methanesulfonamide / 2-methyl-propan-2-ol; H2O / 48 h / 0 °C 3: 18 mg / Triton B / methanol / 24 h 4: 66 percent / Et3N; CuI / Pd(PPh3)4 / benzene; tetrahydrofuran / 2 h / 20 °C 5: H2 / Rh(PPh3)3Cl / benzene / 8 h 6: 1.0 mg / Me2S; BF3*Et2O / 0.08 h / 0 °C View Scheme

1.1: 94 percent / Na / liquid ammonia; tetrahydrofuran; 2-methyl-propan-2-ol / 8 h / -40 °C 2.1: 96 percent / aq. AcOH / 1 h / 60 °C 3.1: 95 percent / DMAP; Et3N / CH2Cl2 / 12 h 4.1: Et3N / CH2Cl2 / 0.17 h / -10 °C 5.1: 77 mg / TBAF / tetrahydrofuran / 10 h / 0 - 20 °C 6.1: n-BuLi / tetrahydrofuran; hexane / 0.5 h / -78 °C 6.2: BF3*Et2O / tetrahydrofuran; hexane / 1 h 7.1: 69 mg / TBAF / tetrahydrofuran / 5 h / 0 - 20 °C 8.1: Et3N / CH2Cl2 / 0.17 h / -10 °C 9.1: AD mix α; methanesulfonamide / 2-methyl-propan-2-ol; H2O / 48 h / 0 °C 10.1: 18 mg / Triton B / methanol / 24 h 11.1: 66 percent / Et3N; CuI / Pd(PPh3)4 / benzene; tetrahydrofuran / 2 h / 20 °C 12.1: H2 / Rh(PPh3)3Cl / benzene / 8 h 13.1: 1.0 mg / Me2S; BF3*Et2O / 0.08 h / 0 °C View Scheme