1.1: 97 percent / DBU / methanol / 1 h / 0 °C 2.1: BuLi / tetrahydrofuran; hexane / 1 h / -78 °C 2.2: MeCuCNLi / tetrahydrofuran; hexane; diethyl ether / 1 h / -78 °C 2.3: 92.6 percent / tetrahydrofuran; hexane; diethyl ether / 1 h / -78 °C 3.1: 131 mg / (S)-2-methyl-CBS-oxazaborolidine; BH3*Me2S / tetrahydrofuran; toluene / 0.25 h / 0 °C 4.1: 96.4 percent / diethyl ether / 1 h / 0 °C 5.1: 72 percent / Li-naphthalene / tetrahydrofuran / -25 °C 6.1: MnO2 / CH2Cl2 / 3 h / Heating 7.1: 33.6 mg / NaH2PO4; 2-methyl-2-butene; NaClO2 / 2-methyl-propan-2-ol; H2O / 20 °C 8.1: NEt3; 2,4,6-trichlorobenzoyl chloride / tetrahydrofuran / 6 h 8.2: 81 percent / DMAP / tetrahydrofuran; toluene / Heating 9.1: 91 percent / aq. HCl / tetrahydrofuran; H2O / 48 h / 20 °C View Scheme

1.1: 84 percent / PhOH / 4.5 h / 125 °C 2.1: 97 percent / NaBH4 / ethanol / 8 h / 20 °C 3.1: 85 percent / I2; Ph3P; imidazole / diethyl ether; acetonitrile / 0.5 h / 20 °C 4.1: 92 percent / LHMDS / tetrahydrofuran / 0.83 h / 0 °C 5.1: 95 percent / Li / tetrahydrofuran; ethanol; liquid ammonia / 0.5 h / -78 °C 6.1: 86 percent / Et3N; DMAP / CH2Cl2 / 1.5 h / 20 °C 7.1: 98 percent / NaI / butan-2-one / 1.5 h / Heating 8.1: 75 percent / urea; NaNO2 / dimethylsulfoxide / 15 h / 20 °C 9.1: 95 percent / imidazole / dimethylformamide / 5 h / 20 °C 10.1: 85 percent / p-chlorophenyl isocyanate; Et3N / benzene / 10 h / Heating 11.1: Mo(CO)6 / H2O; acetonitrile / 1.5 h / Heating 12.1: 35 mg / MsCl; Et3N / CH2Cl2 / 2 h / 20 °C 13.1: 97 percent / PPTS / ethanol / 10 h / 50 °C 14.1: LiOH / H2O; tetrahydrofuran / 0.33 h / 5 °C 15.1: Et3N; 2,4,6-trichlorobenzoyl chloride / tetrahydrofuran / 3 h / 20 °C 15.2: 5.5 mg / DMAP / toluene / 14 h / Heating 16.1: 85 percent / NaBH4 / methanol / 0.5 h / -78 °C 17.1: 95 percent / BF3*Et2O; thiophenol / CH2Cl2 / 0.5 h / 20 °C View Scheme

1.1: 93 percent / DMAP; DCC / CH2Cl2 / 3 h / 20 °C 2.1: LHMDS; TMSCl; Et3N / tetrahydrofuran / -78 - 20 °C 2.2: 86 percent / diethyl ether / 0.5 h / 20 °C 3.1: 86 percent / DDQ / CH2Cl2; H2O / 0.33 h / 20 °C 4.1: 84 percent / PhOH / 4.5 h / 125 °C 5.1: 97 percent / NaBH4 / ethanol / 8 h / 20 °C 6.1: 85 percent / I2; Ph3P; imidazole / diethyl ether; acetonitrile / 0.5 h / 20 °C 7.1: 92 percent / LHMDS / tetrahydrofuran / 0.83 h / 0 °C 8.1: 95 percent / Li / tetrahydrofuran; ethanol; liquid ammonia / 0.5 h / -78 °C 9.1: 86 percent / Et3N; DMAP / CH2Cl2 / 1.5 h / 20 °C 10.1: 98 percent / NaI / butan-2-one / 1.5 h / Heating 11.1: 75 percent / urea; NaNO2 / dimethylsulfoxide / 15 h / 20 °C 12.1: 95 percent / imidazole / dimethylformamide / 5 h / 20 °C 13.1: 85 percent / p-chlorophenyl isocyanate; Et3N / benzene / 10 h / Heating 14.1: Mo(CO)6 / H2O; acetonitrile / 1.5 h / Heating 15.1: 35 mg / MsCl; Et3N / CH2Cl2 / 2 h / 20 °C 16.1: 97 percent / PPTS / ethanol / 10 h / 50 °C 17.1: LiOH / H2O; tetrahydrofuran / 0.33 h / 5 °C 18.1: Et3N; 2,4,6-trichlorobenzoyl chloride / tetrahydrofuran / 3 h / 20 °C 18.2: 5.5 mg / DMAP / toluene / 14 h / Heating 19.1: 85 percent / NaBH4 / methanol / 0.5 h / -78 °C 20.1: 95 percent / BF3*Et2O; thiophenol / CH2Cl2 / 0.5 h / 20 °C View Scheme

1.1: DIBALH / diethyl ether / 1 h / -78 °C 1.2: 63 percent / tetrahydrofuran; diethyl ether / -78 - 20 °C 2.1: 93 percent / DMAP; DCC / CH2Cl2 / 3 h / 20 °C 3.1: LHMDS; TMSCl; Et3N / tetrahydrofuran / -78 - 20 °C 3.2: 86 percent / diethyl ether / 0.5 h / 20 °C 4.1: 86 percent / DDQ / CH2Cl2; H2O / 0.33 h / 20 °C 5.1: 84 percent / PhOH / 4.5 h / 125 °C 6.1: 97 percent / NaBH4 / ethanol / 8 h / 20 °C 7.1: 85 percent / I2; Ph3P; imidazole / diethyl ether; acetonitrile / 0.5 h / 20 °C 8.1: 92 percent / LHMDS / tetrahydrofuran / 0.83 h / 0 °C 9.1: 95 percent / Li / tetrahydrofuran; ethanol; liquid ammonia / 0.5 h / -78 °C 10.1: 86 percent / Et3N; DMAP / CH2Cl2 / 1.5 h / 20 °C 11.1: 98 percent / NaI / butan-2-one / 1.5 h / Heating 12.1: 75 percent / urea; NaNO2 / dimethylsulfoxide / 15 h / 20 °C 13.1: 95 percent / imidazole / dimethylformamide / 5 h / 20 °C 14.1: 85 percent / p-chlorophenyl isocyanate; Et3N / benzene / 10 h / Heating 15.1: Mo(CO)6 / H2O; acetonitrile / 1.5 h / Heating 16.1: 35 mg / MsCl; Et3N / CH2Cl2 / 2 h / 20 °C 17.1: 97 percent / PPTS / ethanol / 10 h / 50 °C 18.1: LiOH / H2O; tetrahydrofuran / 0.33 h / 5 °C 19.1: Et3N; 2,4,6-trichlorobenzoyl chloride / tetrahydrofuran / 3 h / 20 °C 19.2: 5.5 mg / DMAP / toluene / 14 h / Heating 20.1: 85 percent / NaBH4 / methanol / 0.5 h / -78 °C 21.1: 95 percent / BF3*Et2O; thiophenol / CH2Cl2 / 0.5 h / 20 °C View Scheme

1.1: 95 percent / Li / tetrahydrofuran; ethanol; liquid ammonia / 0.5 h / -78 °C 2.1: 86 percent / Et3N; DMAP / CH2Cl2 / 1.5 h / 20 °C 3.1: 98 percent / NaI / butan-2-one / 1.5 h / Heating 4.1: 75 percent / urea; NaNO2 / dimethylsulfoxide / 15 h / 20 °C 5.1: 95 percent / imidazole / dimethylformamide / 5 h / 20 °C 6.1: 85 percent / p-chlorophenyl isocyanate; Et3N / benzene / 10 h / Heating 7.1: Mo(CO)6 / H2O; acetonitrile / 1.5 h / Heating 8.1: 35 mg / MsCl; Et3N / CH2Cl2 / 2 h / 20 °C 9.1: 97 percent / PPTS / ethanol / 10 h / 50 °C 10.1: LiOH / H2O; tetrahydrofuran / 0.33 h / 5 °C 11.1: Et3N; 2,4,6-trichlorobenzoyl chloride / tetrahydrofuran / 3 h / 20 °C 11.2: 5.5 mg / DMAP / toluene / 14 h / Heating 12.1: 85 percent / NaBH4 / methanol / 0.5 h / -78 °C 13.1: 95 percent / BF3*Et2O; thiophenol / CH2Cl2 / 0.5 h / 20 °C View Scheme

1.1: LHMDS; TMSCl; Et3N / tetrahydrofuran / -78 - 20 °C 1.2: 86 percent / diethyl ether / 0.5 h / 20 °C 2.1: 86 percent / DDQ / CH2Cl2; H2O / 0.33 h / 20 °C 3.1: 84 percent / PhOH / 4.5 h / 125 °C 4.1: 97 percent / NaBH4 / ethanol / 8 h / 20 °C 5.1: 85 percent / I2; Ph3P; imidazole / diethyl ether; acetonitrile / 0.5 h / 20 °C 6.1: 92 percent / LHMDS / tetrahydrofuran / 0.83 h / 0 °C 7.1: 95 percent / Li / tetrahydrofuran; ethanol; liquid ammonia / 0.5 h / -78 °C 8.1: 86 percent / Et3N; DMAP / CH2Cl2 / 1.5 h / 20 °C 9.1: 98 percent / NaI / butan-2-one / 1.5 h / Heating 10.1: 75 percent / urea; NaNO2 / dimethylsulfoxide / 15 h / 20 °C 11.1: 95 percent / imidazole / dimethylformamide / 5 h / 20 °C 12.1: 85 percent / p-chlorophenyl isocyanate; Et3N / benzene / 10 h / Heating 13.1: Mo(CO)6 / H2O; acetonitrile / 1.5 h / Heating 14.1: 35 mg / MsCl; Et3N / CH2Cl2 / 2 h / 20 °C 15.1: 97 percent / PPTS / ethanol / 10 h / 50 °C 16.1: LiOH / H2O; tetrahydrofuran / 0.33 h / 5 °C 17.1: Et3N; 2,4,6-trichlorobenzoyl chloride / tetrahydrofuran / 3 h / 20 °C 17.2: 5.5 mg / DMAP / toluene / 14 h / Heating 18.1: 85 percent / NaBH4 / methanol / 0.5 h / -78 °C 19.1: 95 percent / BF3*Et2O; thiophenol / CH2Cl2 / 0.5 h / 20 °C View Scheme

1.1: 86 percent / DDQ / CH2Cl2; H2O / 0.33 h / 20 °C 2.1: 84 percent / PhOH / 4.5 h / 125 °C 3.1: 97 percent / NaBH4 / ethanol / 8 h / 20 °C 4.1: 85 percent / I2; Ph3P; imidazole / diethyl ether; acetonitrile / 0.5 h / 20 °C 5.1: 92 percent / LHMDS / tetrahydrofuran / 0.83 h / 0 °C 6.1: 95 percent / Li / tetrahydrofuran; ethanol; liquid ammonia / 0.5 h / -78 °C 7.1: 86 percent / Et3N; DMAP / CH2Cl2 / 1.5 h / 20 °C 8.1: 98 percent / NaI / butan-2-one / 1.5 h / Heating 9.1: 75 percent / urea; NaNO2 / dimethylsulfoxide / 15 h / 20 °C 10.1: 95 percent / imidazole / dimethylformamide / 5 h / 20 °C 11.1: 85 percent / p-chlorophenyl isocyanate; Et3N / benzene / 10 h / Heating 12.1: Mo(CO)6 / H2O; acetonitrile / 1.5 h / Heating 13.1: 35 mg / MsCl; Et3N / CH2Cl2 / 2 h / 20 °C 14.1: 97 percent / PPTS / ethanol / 10 h / 50 °C 15.1: LiOH / H2O; tetrahydrofuran / 0.33 h / 5 °C 16.1: Et3N; 2,4,6-trichlorobenzoyl chloride / tetrahydrofuran / 3 h / 20 °C 16.2: 5.5 mg / DMAP / toluene / 14 h / Heating 17.1: 85 percent / NaBH4 / methanol / 0.5 h / -78 °C 18.1: 95 percent / BF3*Et2O; thiophenol / CH2Cl2 / 0.5 h / 20 °C View Scheme

1.1: Et3N; 2,4,6-trichlorobenzoyl chloride / tetrahydrofuran / 3 h / 20 °C 1.2: 5.5 mg / DMAP / toluene / 14 h / Heating 2.1: 85 percent / NaBH4 / methanol / 0.5 h / -78 °C 3.1: 95 percent / BF3*Et2O; thiophenol / CH2Cl2 / 0.5 h / 20 °C View Scheme

1.1: 95 percent / imidazole / dimethylformamide / 5 h / 20 °C 2.1: 85 percent / p-chlorophenyl isocyanate; Et3N / benzene / 10 h / Heating 3.1: Mo(CO)6 / H2O; acetonitrile / 1.5 h / Heating 4.1: 35 mg / MsCl; Et3N / CH2Cl2 / 2 h / 20 °C 5.1: 97 percent / PPTS / ethanol / 10 h / 50 °C 6.1: LiOH / H2O; tetrahydrofuran / 0.33 h / 5 °C 7.1: Et3N; 2,4,6-trichlorobenzoyl chloride / tetrahydrofuran / 3 h / 20 °C 7.2: 5.5 mg / DMAP / toluene / 14 h / Heating 8.1: 85 percent / NaBH4 / methanol / 0.5 h / -78 °C 9.1: 95 percent / BF3*Et2O; thiophenol / CH2Cl2 / 0.5 h / 20 °C View Scheme

1: 85 percent / NaBH4 / methanol / 0.5 h / -78 °C 2: 95 percent / BF3*Et2O; thiophenol / CH2Cl2 / 0.5 h / 20 °C View Scheme