in N,N-dimethyl-formamide T=23°C; 3 h;

1: HN3, ADDP, Me3P 2: H+ 3: H2 / Rh/C 4: 76 percent / dimethylformamide / 3 h / 23 °C View Scheme

1: H+ 2: HN3, ADDP, Me3P 3: H+ 4: H2 / Rh/C 5: 76 percent / dimethylformamide / 3 h / 23 °C View Scheme

bis-(2-oxo-3-oxazolidinyl)phosphoryl chloride; triethylamine in N,N-dimethyl acetamide

1: 1.) NaH / 1.) THF, RT, 45 min, 2.) THF, RT, 45 min 2: PCC, NaOAc, silica / CH2Cl2 / 4 h / 0 - 20 °C 3: 1.) NaH / 1.) THF, 0 deg C, 30 min, 2.) THF, from 0 deg C to RT, 2 h 4: 63 percent / LiTi(Oi-Pr)4(SPh) / tetrahydrofuran; hexane / 72 h / Ambient temperature 5: 91 percent / DIBAL-H / hexane; CH2Cl2 / 4 h / -78 °C 6: 90 percent / chiral dioxaborolane catalyst / CH2Cl2; hexane / 168 h / -40 °C 7: 1.) n-Bu3P / 1.) benzene, RT, 10 min, 2.) benzene, RT, 1.5 h 8: W-2 Raney nickel / ethanol / 48 h / -60 °C 9: NH4F / ethanol / 26 h / 65 °C 10: PCC, NaOAc, silica / CH2Cl2 / 4 h / 0 - 20 °C 11: 1.) NaH / 1.) THF, 0 deg C, 30 min, 2.) THF, from 0 deg C to RT, 2 h 12: 85 percent / potassium trimethylsilanolate / CH2Cl2 / Ambient temperature 13: Et3N / N,N-dimethyl-acetamide / 3 h / Ambient temperature 14: Et3N / 24 h / Ambient temperature View Scheme

1: 50 percent / LiTi(Oi-Pr)4(SPh) / tetrahydrofuran; hexane / 72 h / Ambient temperature 2: 94 percent / DIBAL-H / hexane; CH2Cl2 / 4 h / -78 °C 3: 93 percent / chiral dioxaborolane catalyst / CH2Cl2 / 40 h / Ambient temperature 4: 1.) NaH / 1.) THF, RT, 45 min, 2.) THF, RT, 45 min 5: PCC, NaOAc, silica / CH2Cl2 / 4 h / 0 - 20 °C 6: 1.) NaH / 1.) THF, 0 deg C, 30 min, 2.) THF, from 0 deg C to RT, 2 h 7: 63 percent / LiTi(Oi-Pr)4(SPh) / tetrahydrofuran; hexane / 72 h / Ambient temperature 8: 91 percent / DIBAL-H / hexane; CH2Cl2 / 4 h / -78 °C 9: 90 percent / chiral dioxaborolane catalyst / CH2Cl2; hexane / 168 h / -40 °C 10: 1.) n-Bu3P / 1.) benzene, RT, 10 min, 2.) benzene, RT, 1.5 h 11: W-2 Raney nickel / ethanol / 48 h / -60 °C 12: NH4F / ethanol / 26 h / 65 °C 13: PCC, NaOAc, silica / CH2Cl2 / 4 h / 0 - 20 °C 14: 1.) NaH / 1.) THF, 0 deg C, 30 min, 2.) THF, from 0 deg C to RT, 2 h 15: 85 percent / potassium trimethylsilanolate / CH2Cl2 / Ambient temperature 16: Et3N / N,N-dimethyl-acetamide / 3 h / Ambient temperature 17: Et3N / 24 h / Ambient temperature View Scheme

1: 94 percent / DIBAL-H / hexane; CH2Cl2 / 4 h / -78 °C 2: 93 percent / chiral dioxaborolane catalyst / CH2Cl2 / 40 h / Ambient temperature 3: 1.) NaH / 1.) THF, RT, 45 min, 2.) THF, RT, 45 min 4: PCC, NaOAc, silica / CH2Cl2 / 4 h / 0 - 20 °C 5: 1.) NaH / 1.) THF, 0 deg C, 30 min, 2.) THF, from 0 deg C to RT, 2 h 6: 63 percent / LiTi(Oi-Pr)4(SPh) / tetrahydrofuran; hexane / 72 h / Ambient temperature 7: 91 percent / DIBAL-H / hexane; CH2Cl2 / 4 h / -78 °C 8: 90 percent / chiral dioxaborolane catalyst / CH2Cl2; hexane / 168 h / -40 °C 9: 1.) n-Bu3P / 1.) benzene, RT, 10 min, 2.) benzene, RT, 1.5 h 10: W-2 Raney nickel / ethanol / 48 h / -60 °C 11: NH4F / ethanol / 26 h / 65 °C 12: PCC, NaOAc, silica / CH2Cl2 / 4 h / 0 - 20 °C 13: 1.) NaH / 1.) THF, 0 deg C, 30 min, 2.) THF, from 0 deg C to RT, 2 h 14: 85 percent / potassium trimethylsilanolate / CH2Cl2 / Ambient temperature 15: Et3N / N,N-dimethyl-acetamide / 3 h / Ambient temperature 16: Et3N / 24 h / Ambient temperature View Scheme

1: PCC, NaOAc, silica / CH2Cl2 / 4 h / 0 - 20 °C 2: 1.) NaH / 1.) THF, 0 deg C, 30 min, 2.) THF, from 0 deg C to RT, 2 h 3: 63 percent / LiTi(Oi-Pr)4(SPh) / tetrahydrofuran; hexane / 72 h / Ambient temperature 4: 91 percent / DIBAL-H / hexane; CH2Cl2 / 4 h / -78 °C 5: 90 percent / chiral dioxaborolane catalyst / CH2Cl2; hexane / 168 h / -40 °C 6: 1.) n-Bu3P / 1.) benzene, RT, 10 min, 2.) benzene, RT, 1.5 h 7: W-2 Raney nickel / ethanol / 48 h / -60 °C 8: NH4F / ethanol / 26 h / 65 °C 9: PCC, NaOAc, silica / CH2Cl2 / 4 h / 0 - 20 °C 10: 1.) NaH / 1.) THF, 0 deg C, 30 min, 2.) THF, from 0 deg C to RT, 2 h 11: 85 percent / potassium trimethylsilanolate / CH2Cl2 / Ambient temperature 12: Et3N / N,N-dimethyl-acetamide / 3 h / Ambient temperature 13: Et3N / 24 h / Ambient temperature View Scheme

1: 90 percent / chiral dioxaborolane catalyst / CH2Cl2; hexane / 168 h / -40 °C 2: 1.) n-Bu3P / 1.) benzene, RT, 10 min, 2.) benzene, RT, 1.5 h 3: W-2 Raney nickel / ethanol / 48 h / -60 °C 4: NH4F / ethanol / 26 h / 65 °C 5: PCC, NaOAc, silica / CH2Cl2 / 4 h / 0 - 20 °C 6: 1.) NaH / 1.) THF, 0 deg C, 30 min, 2.) THF, from 0 deg C to RT, 2 h 7: 85 percent / potassium trimethylsilanolate / CH2Cl2 / Ambient temperature 8: Et3N / N,N-dimethyl-acetamide / 3 h / Ambient temperature 9: Et3N / 24 h / Ambient temperature View Scheme

1: W-2 Raney nickel / ethanol / 48 h / -60 °C 2: NH4F / ethanol / 26 h / 65 °C 3: PCC, NaOAc, silica / CH2Cl2 / 4 h / 0 - 20 °C 4: 1.) NaH / 1.) THF, 0 deg C, 30 min, 2.) THF, from 0 deg C to RT, 2 h 5: 85 percent / potassium trimethylsilanolate / CH2Cl2 / Ambient temperature 6: Et3N / N,N-dimethyl-acetamide / 3 h / Ambient temperature 7: Et3N / 24 h / Ambient temperature View Scheme