1.1: Et3N / 10 h / 20 °C 2.1: 71 percent / DIPEA; DMAP / CH2Cl2 / 6 h / 20 °C 3.1: 94 percent / H2 / Pd(OH)2/C / ethyl acetate / 12 h 4.1: LDA / tetrahydrofuran / 1 h / -50 °C 4.2: 75 percent / tetrahydrofuran; hexamethylphosphoric acid triamide / 3 h / -50 - 0 °C 5.1: LiOH; H2O / tetrahydrofuran; methanol / 12 h / 0 - 20 °C 6.1: 210 mg / PhSO2Cl; pyridine / 12 h / 0 °C 7.1: 88 percent / BF3*Et2O; ethane-1,2-dithiol / CH2Cl2 / 1 h / 0 °C View Scheme

1.1: 94 percent / H2 / Pd(OH)2/C / ethyl acetate / 12 h 2.1: LDA / tetrahydrofuran / 1 h / -50 °C 2.2: 75 percent / tetrahydrofuran; hexamethylphosphoric acid triamide / 3 h / -50 - 0 °C 3.1: LiOH; H2O / tetrahydrofuran; methanol / 12 h / 0 - 20 °C 4.1: 210 mg / PhSO2Cl; pyridine / 12 h / 0 °C 5.1: 88 percent / BF3*Et2O; ethane-1,2-dithiol / CH2Cl2 / 1 h / 0 °C View Scheme

1.1: 78 percent / NaH; TBAI / tetrahydrofuran / 4 h / Heating 2.1: 79 percent / PTSA / methanol / 12 h 3.1: 83 percent / imidazole / CH2Cl2 / 4 h / 20 °C 4.1: NaH / 4 h 4.2: 78 percent / 12 h 5.1: 79 percent / AIBN; n-Bu3SnH / toluene / 1.5 h / Heating 6.1: 98 percent / TBAF / tetrahydrofuran / 2 h / 25 °C 7.1: 92 percent / Et3N / CH2Cl2 / 3 h / 20 °C 8.1: 76 percent / CuBr / tetrahydrofuran; diethyl ether / 5 h / 20 °C 9.1: 72 percent / aq. AcOH / 4 h / Heating 10.1: 84 percent / Dess-Martin periodinane / CH2Cl2 / 1 h / 0 °C 11.1: Et3N / 10 h / 20 °C 12.1: 71 percent / DIPEA; DMAP / CH2Cl2 / 6 h / 20 °C 13.1: 94 percent / H2 / Pd(OH)2/C / ethyl acetate / 12 h 14.1: LDA / tetrahydrofuran / 1 h / -50 °C 14.2: 75 percent / tetrahydrofuran; hexamethylphosphoric acid triamide / 3 h / -50 - 0 °C 15.1: LiOH; H2O / tetrahydrofuran; methanol / 12 h / 0 - 20 °C 16.1: 210 mg / PhSO2Cl; pyridine / 12 h / 0 °C 17.1: 88 percent / BF3*Et2O; ethane-1,2-dithiol / CH2Cl2 / 1 h / 0 °C View Scheme

1.1: NaOMe / methanol / 1 h / 20 °C 2.1: 7.4 g / PTSA / toluene / 6 h / Heating 3.1: 78 percent / NaH; TBAI / tetrahydrofuran / 4 h / Heating 4.1: 79 percent / PTSA / methanol / 12 h 5.1: 83 percent / imidazole / CH2Cl2 / 4 h / 20 °C 6.1: NaH / 4 h 6.2: 78 percent / 12 h 7.1: 79 percent / AIBN; n-Bu3SnH / toluene / 1.5 h / Heating 8.1: 98 percent / TBAF / tetrahydrofuran / 2 h / 25 °C 9.1: 92 percent / Et3N / CH2Cl2 / 3 h / 20 °C 10.1: 76 percent / CuBr / tetrahydrofuran; diethyl ether / 5 h / 20 °C 11.1: 72 percent / aq. AcOH / 4 h / Heating 12.1: 84 percent / Dess-Martin periodinane / CH2Cl2 / 1 h / 0 °C 13.1: Et3N / 10 h / 20 °C 14.1: 71 percent / DIPEA; DMAP / CH2Cl2 / 6 h / 20 °C 15.1: 94 percent / H2 / Pd(OH)2/C / ethyl acetate / 12 h 16.1: LDA / tetrahydrofuran / 1 h / -50 °C 16.2: 75 percent / tetrahydrofuran; hexamethylphosphoric acid triamide / 3 h / -50 - 0 °C 17.1: LiOH; H2O / tetrahydrofuran; methanol / 12 h / 0 - 20 °C 18.1: 210 mg / PhSO2Cl; pyridine / 12 h / 0 °C 19.1: 88 percent / BF3*Et2O; ethane-1,2-dithiol / CH2Cl2 / 1 h / 0 °C View Scheme

1.1: 92 percent / Et3N / CH2Cl2 / 3 h / 20 °C 2.1: 76 percent / CuBr / tetrahydrofuran; diethyl ether / 5 h / 20 °C 3.1: 72 percent / aq. AcOH / 4 h / Heating 4.1: 84 percent / Dess-Martin periodinane / CH2Cl2 / 1 h / 0 °C 5.1: Et3N / 10 h / 20 °C 6.1: 71 percent / DIPEA; DMAP / CH2Cl2 / 6 h / 20 °C 7.1: 94 percent / H2 / Pd(OH)2/C / ethyl acetate / 12 h 8.1: LDA / tetrahydrofuran / 1 h / -50 °C 8.2: 75 percent / tetrahydrofuran; hexamethylphosphoric acid triamide / 3 h / -50 - 0 °C 9.1: LiOH; H2O / tetrahydrofuran; methanol / 12 h / 0 - 20 °C 10.1: 210 mg / PhSO2Cl; pyridine / 12 h / 0 °C 11.1: 88 percent / BF3*Et2O; ethane-1,2-dithiol / CH2Cl2 / 1 h / 0 °C View Scheme

1.1: 79 percent / PTSA / methanol / 12 h 2.1: 83 percent / imidazole / CH2Cl2 / 4 h / 20 °C 3.1: NaH / 4 h 3.2: 78 percent / 12 h 4.1: 79 percent / AIBN; n-Bu3SnH / toluene / 1.5 h / Heating 5.1: 98 percent / TBAF / tetrahydrofuran / 2 h / 25 °C 6.1: 92 percent / Et3N / CH2Cl2 / 3 h / 20 °C 7.1: 76 percent / CuBr / tetrahydrofuran; diethyl ether / 5 h / 20 °C 8.1: 72 percent / aq. AcOH / 4 h / Heating 9.1: 84 percent / Dess-Martin periodinane / CH2Cl2 / 1 h / 0 °C 10.1: Et3N / 10 h / 20 °C 11.1: 71 percent / DIPEA; DMAP / CH2Cl2 / 6 h / 20 °C 12.1: 94 percent / H2 / Pd(OH)2/C / ethyl acetate / 12 h 13.1: LDA / tetrahydrofuran / 1 h / -50 °C 13.2: 75 percent / tetrahydrofuran; hexamethylphosphoric acid triamide / 3 h / -50 - 0 °C 14.1: LiOH; H2O / tetrahydrofuran; methanol / 12 h / 0 - 20 °C 15.1: 210 mg / PhSO2Cl; pyridine / 12 h / 0 °C 16.1: 88 percent / BF3*Et2O; ethane-1,2-dithiol / CH2Cl2 / 1 h / 0 °C View Scheme

1.1: 7.4 g / PTSA / toluene / 6 h / Heating 2.1: 78 percent / NaH; TBAI / tetrahydrofuran / 4 h / Heating 3.1: 79 percent / PTSA / methanol / 12 h 4.1: 83 percent / imidazole / CH2Cl2 / 4 h / 20 °C 5.1: NaH / 4 h 5.2: 78 percent / 12 h 6.1: 79 percent / AIBN; n-Bu3SnH / toluene / 1.5 h / Heating 7.1: 98 percent / TBAF / tetrahydrofuran / 2 h / 25 °C 8.1: 92 percent / Et3N / CH2Cl2 / 3 h / 20 °C 9.1: 76 percent / CuBr / tetrahydrofuran; diethyl ether / 5 h / 20 °C 10.1: 72 percent / aq. AcOH / 4 h / Heating 11.1: 84 percent / Dess-Martin periodinane / CH2Cl2 / 1 h / 0 °C 12.1: Et3N / 10 h / 20 °C 13.1: 71 percent / DIPEA; DMAP / CH2Cl2 / 6 h / 20 °C 14.1: 94 percent / H2 / Pd(OH)2/C / ethyl acetate / 12 h 15.1: LDA / tetrahydrofuran / 1 h / -50 °C 15.2: 75 percent / tetrahydrofuran; hexamethylphosphoric acid triamide / 3 h / -50 - 0 °C 16.1: LiOH; H2O / tetrahydrofuran; methanol / 12 h / 0 - 20 °C 17.1: 210 mg / PhSO2Cl; pyridine / 12 h / 0 °C 18.1: 88 percent / BF3*Et2O; ethane-1,2-dithiol / CH2Cl2 / 1 h / 0 °C View Scheme

1.1: 83 percent / imidazole / CH2Cl2 / 4 h / 20 °C 2.1: NaH / 4 h 2.2: 78 percent / 12 h 3.1: 79 percent / AIBN; n-Bu3SnH / toluene / 1.5 h / Heating 4.1: 98 percent / TBAF / tetrahydrofuran / 2 h / 25 °C 5.1: 92 percent / Et3N / CH2Cl2 / 3 h / 20 °C 6.1: 76 percent / CuBr / tetrahydrofuran; diethyl ether / 5 h / 20 °C 7.1: 72 percent / aq. AcOH / 4 h / Heating 8.1: 84 percent / Dess-Martin periodinane / CH2Cl2 / 1 h / 0 °C 9.1: Et3N / 10 h / 20 °C 10.1: 71 percent / DIPEA; DMAP / CH2Cl2 / 6 h / 20 °C 11.1: 94 percent / H2 / Pd(OH)2/C / ethyl acetate / 12 h 12.1: LDA / tetrahydrofuran / 1 h / -50 °C 12.2: 75 percent / tetrahydrofuran; hexamethylphosphoric acid triamide / 3 h / -50 - 0 °C 13.1: LiOH; H2O / tetrahydrofuran; methanol / 12 h / 0 - 20 °C 14.1: 210 mg / PhSO2Cl; pyridine / 12 h / 0 °C 15.1: 88 percent / BF3*Et2O; ethane-1,2-dithiol / CH2Cl2 / 1 h / 0 °C View Scheme

1.1: 98 percent / TBAF / tetrahydrofuran / 2 h / 25 °C 2.1: 92 percent / Et3N / CH2Cl2 / 3 h / 20 °C 3.1: 76 percent / CuBr / tetrahydrofuran; diethyl ether / 5 h / 20 °C 4.1: 72 percent / aq. AcOH / 4 h / Heating 5.1: 84 percent / Dess-Martin periodinane / CH2Cl2 / 1 h / 0 °C 6.1: Et3N / 10 h / 20 °C 7.1: 71 percent / DIPEA; DMAP / CH2Cl2 / 6 h / 20 °C 8.1: 94 percent / H2 / Pd(OH)2/C / ethyl acetate / 12 h 9.1: LDA / tetrahydrofuran / 1 h / -50 °C 9.2: 75 percent / tetrahydrofuran; hexamethylphosphoric acid triamide / 3 h / -50 - 0 °C 10.1: LiOH; H2O / tetrahydrofuran; methanol / 12 h / 0 - 20 °C 11.1: 210 mg / PhSO2Cl; pyridine / 12 h / 0 °C 12.1: 88 percent / BF3*Et2O; ethane-1,2-dithiol / CH2Cl2 / 1 h / 0 °C View Scheme

1: 94 percent / NaH; TBAI / tetrahydrofuran / 0 - 20 °C 2: 92 percent / BF3*OEt2; ethane dithiol / CH2Cl2 / 1 h / 0 - 20 °C 3: TEMPO; BAIB / CH2Cl2 / 20 °C 4: NaClO2; NaH2PO4 5: 78 percent / PhSO2Cl; pyridine / 12 h / 0 °C 6: 91 percent / H2 / Pd(OH)2 / ethyl acetate / 12 h View Scheme