1: 72 percent / pyridinium dichromate / 1,2-dichloro-ethane / 8 h / Heating 2: 98 percent / H2 / PtO2 / ethanol / 3 h / 23 °C 3: 96 percent / tetrahydrofuran / 1.5 h / -78 °C 4: 39 percent / Et3SiH; BF3*OEt2 / CH2Cl2; 2,2,2-trifluoro-ethanol / 3 h / -78 °C 5: TFA / CH2Cl2 / 0 - 23 °C 6: 86 percent / N,N-diisopropylethylamine; HATU / acetonitrile / 12 h / 23 °C 7: 67 percent / Grela's catalyst / CH2Cl2 / 9 h / 23 °C 8: 90 percent / tetrahydrofuran / 0 - 23 °C 9: 28 percent / Grela's catalyst / 1,2-dichloro-ethane / 10 h / 23 °C View Scheme

1: 98 percent / H2 / PtO2 / ethanol / 3 h / 23 °C 2: 96 percent / tetrahydrofuran / 1.5 h / -78 °C 3: 39 percent / Et3SiH; BF3*OEt2 / CH2Cl2; 2,2,2-trifluoro-ethanol / 3 h / -78 °C 4: TFA / CH2Cl2 / 0 - 23 °C 5: 86 percent / N,N-diisopropylethylamine; HATU / acetonitrile / 12 h / 23 °C 6: 67 percent / Grela's catalyst / CH2Cl2 / 9 h / 23 °C 7: 90 percent / tetrahydrofuran / 0 - 23 °C 8: 28 percent / Grela's catalyst / 1,2-dichloro-ethane / 10 h / 23 °C View Scheme

1: 98 percent / Grubbs' 2nd catalyst / benzene / 0.5 h / Heating 2: 72 percent / pyridinium dichromate / 1,2-dichloro-ethane / 8 h / Heating 3: 98 percent / H2 / PtO2 / ethanol / 3 h / 23 °C 4: 96 percent / tetrahydrofuran / 1.5 h / -78 °C 5: 39 percent / Et3SiH; BF3*OEt2 / CH2Cl2; 2,2,2-trifluoro-ethanol / 3 h / -78 °C 6: TFA / CH2Cl2 / 0 - 23 °C 7: 86 percent / N,N-diisopropylethylamine; HATU / acetonitrile / 12 h / 23 °C 8: 67 percent / Grela's catalyst / CH2Cl2 / 9 h / 23 °C 9: 90 percent / tetrahydrofuran / 0 - 23 °C 10: 28 percent / Grela's catalyst / 1,2-dichloro-ethane / 10 h / 23 °C View Scheme

toluene-4-sulfonic acid in tetrahydrofuran; water T=20°C; 2 h; Title compound not separated from byproducts.;

1.1: (1R,2S)-tridentate chromium catalyst; 4 Angstroem molecular sieves / 11 h / 20 °C 2.1: 775.4 mg / m-CPBA; aq. NaHCO3 / toluene / 0.5 h / 0 °C 3.1: methanol / 3 h / 20 °C 4.1: NaCNBH3 / tetrahydrofuran; methanol; ethanol / 1.67 h / 0 °C / pH 4 5.1: 570.5 mg / NaOAc*3H2O / ethanol / 0.33 h / 75 °C 6.1: 99 percent / TBAF / tetrahydrofuran / 0.25 h / 0 °C 7.1: 100 percent / t-BuOK / dimethylsulfoxide / 0.03 h / 20 °C 8.1: Cp2Zr(H)Cl / tetrahydrofuran / 2.33 h / 20 - 50 °C 8.2: 65 percent / I2 / tetrahydrofuran / 0.25 h / 0 °C 9.1: pyridine; DMAP / CH2Cl2 / 3 h / 20 °C 10.1: 67.7 mg / LiN3; DMPU / 36 h / 50 - 55 °C 11.1: Cp2Zr(H)Cl / tetrahydrofuran / 0.67 h / 0 °C 11.2: ZnCl2 / tetrahydrofuran / 0.17 h / 0 °C 11.3: 80 percent / Pd(PPh3)4 / tetrahydrofuran / 0.83 h / 0 - 20 °C 12.1: Me3P / tetrahydrofuran / 4 h / 20 °C 12.2: H2O / tetrahydrofuran / 1.5 h / 20 °C 13.1: 30.4 mg / DIPEA; HATU / acetonitrile / 0.5 h / 20 °C 14.1: DBU / dimethylformamide / 60 h / 20 °C 15.1: 16.2 mg / TBAF; AcOH / tetrahydrofuran / 0.25 h / 0 °C 16.1: TsOH*H2O / tetrahydrofuran; H2O / 2 h / 20 °C View Scheme

1.1: (1R,2S)-tridentate chromium catalyst; 4 Angstroem molecular sieves / 11 h / 20 °C 2.1: 775.4 mg / m-CPBA; aq. NaHCO3 / toluene / 0.5 h / 0 °C 3.1: methanol / 3 h / 20 °C 4.1: NaCNBH3 / tetrahydrofuran; methanol; ethanol / 1.67 h / 0 °C / pH 4 5.1: 570.5 mg / NaOAc*3H2O / ethanol / 0.33 h / 75 °C 6.1: 99 percent / TBAF / tetrahydrofuran / 0.25 h / 0 °C 7.1: 100 percent / t-BuOK / dimethylsulfoxide / 0.03 h / 20 °C 8.1: Cp2Zr(H)Cl / tetrahydrofuran / 2.33 h / 20 - 50 °C 8.2: 65 percent / I2 / tetrahydrofuran / 0.25 h / 0 °C 9.1: pyridine; DMAP / CH2Cl2 / 3 h / 20 °C 10.1: 67.7 mg / LiN3; DMPU / 36 h / 50 - 55 °C 11.1: Cp2Zr(H)Cl / tetrahydrofuran / 0.67 h / 0 °C 11.2: ZnCl2 / tetrahydrofuran / 0.17 h / 0 °C 11.3: 80 percent / Pd(PPh3)4 / tetrahydrofuran / 0.83 h / 0 - 20 °C 12.1: Me3P / tetrahydrofuran / 4 h / 20 °C 12.2: H2O / tetrahydrofuran / 1.5 h / 20 °C 13.1: 30.4 mg / DIPEA; HATU / acetonitrile / 0.5 h / 20 °C 14.1: DBU / dimethylformamide / 60 h / 20 °C 15.1: 16.2 mg / TBAF; AcOH / tetrahydrofuran / 0.25 h / 0 °C 16.1: TsOH*H2O / tetrahydrofuran; H2O / 2 h / 20 °C View Scheme

1.1: Cp2Zr(H)Cl / tetrahydrofuran / 2.33 h / 20 - 50 °C 1.2: 65 percent / I2 / tetrahydrofuran / 0.25 h / 0 °C 2.1: pyridine; DMAP / CH2Cl2 / 3 h / 20 °C 3.1: 67.7 mg / LiN3; DMPU / 36 h / 50 - 55 °C 4.1: Cp2Zr(H)Cl / tetrahydrofuran / 0.67 h / 0 °C 4.2: ZnCl2 / tetrahydrofuran / 0.17 h / 0 °C 4.3: 80 percent / Pd(PPh3)4 / tetrahydrofuran / 0.83 h / 0 - 20 °C 5.1: Me3P / tetrahydrofuran / 4 h / 20 °C 5.2: H2O / tetrahydrofuran / 1.5 h / 20 °C 6.1: 30.4 mg / DIPEA; HATU / acetonitrile / 0.5 h / 20 °C 7.1: DBU / dimethylformamide / 60 h / 20 °C 8.1: 16.2 mg / TBAF; AcOH / tetrahydrofuran / 0.25 h / 0 °C 9.1: TsOH*H2O / tetrahydrofuran; H2O / 2 h / 20 °C View Scheme

1.1: 100 percent / t-BuOK / dimethylsulfoxide / 0.03 h / 20 °C 2.1: Cp2Zr(H)Cl / tetrahydrofuran / 2.33 h / 20 - 50 °C 2.2: 65 percent / I2 / tetrahydrofuran / 0.25 h / 0 °C 3.1: pyridine; DMAP / CH2Cl2 / 3 h / 20 °C 4.1: 67.7 mg / LiN3; DMPU / 36 h / 50 - 55 °C 5.1: Cp2Zr(H)Cl / tetrahydrofuran / 0.67 h / 0 °C 5.2: ZnCl2 / tetrahydrofuran / 0.17 h / 0 °C 5.3: 80 percent / Pd(PPh3)4 / tetrahydrofuran / 0.83 h / 0 - 20 °C 6.1: Me3P / tetrahydrofuran / 4 h / 20 °C 6.2: H2O / tetrahydrofuran / 1.5 h / 20 °C 7.1: 30.4 mg / DIPEA; HATU / acetonitrile / 0.5 h / 20 °C 8.1: DBU / dimethylformamide / 60 h / 20 °C 9.1: 16.2 mg / TBAF; AcOH / tetrahydrofuran / 0.25 h / 0 °C 10.1: TsOH*H2O / tetrahydrofuran; H2O / 2 h / 20 °C View Scheme

1.1: Cp2Zr(H)Cl / tetrahydrofuran / 0.67 h / 0 °C 1.2: ZnCl2 / tetrahydrofuran / 0.17 h / 0 °C 1.3: 80 percent / Pd(PPh3)4 / tetrahydrofuran / 0.83 h / 0 - 20 °C 2.1: Me3P / tetrahydrofuran / 4 h / 20 °C 2.2: H2O / tetrahydrofuran / 1.5 h / 20 °C 3.1: 30.4 mg / DIPEA; HATU / acetonitrile / 0.5 h / 20 °C 4.1: DBU / dimethylformamide / 60 h / 20 °C 5.1: 16.2 mg / TBAF; AcOH / tetrahydrofuran / 0.25 h / 0 °C 6.1: TsOH*H2O / tetrahydrofuran; H2O / 2 h / 20 °C View Scheme

1.1: pyridine; DMAP / CH2Cl2 / 3 h / 20 °C 2.1: 67.7 mg / LiN3; DMPU / 36 h / 50 - 55 °C 3.1: Cp2Zr(H)Cl / tetrahydrofuran / 0.67 h / 0 °C 3.2: ZnCl2 / tetrahydrofuran / 0.17 h / 0 °C 3.3: 80 percent / Pd(PPh3)4 / tetrahydrofuran / 0.83 h / 0 - 20 °C 4.1: Me3P / tetrahydrofuran / 4 h / 20 °C 4.2: H2O / tetrahydrofuran / 1.5 h / 20 °C 5.1: 30.4 mg / DIPEA; HATU / acetonitrile / 0.5 h / 20 °C 6.1: DBU / dimethylformamide / 60 h / 20 °C 7.1: 16.2 mg / TBAF; AcOH / tetrahydrofuran / 0.25 h / 0 °C 8.1: TsOH*H2O / tetrahydrofuran; H2O / 2 h / 20 °C View Scheme