1.1: Et3N; 2,4,6-trichlorobenzoyl chloride / tetrahydrofuran / 0.08 h / 0 °C 1.2: 73 percent / DMAP / toluene; tetrahydrofuran / 0.5 h / 20 °C 2.1: 82 percent / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone / CH2Cl2; H2O / 2.5 h 3.1: 90 percent / trifluoroacetic acid / CH2Cl2 / 2.5 h / 20 °C View Scheme

1.1: 95 percent / Dess-Martin periodinane / CH2Cl2 / 2 h / 20 °C 2.1: 62 percent / 2 N NaOH / H2O / 1.5 h / Heating 3.1: Et3N; 2,4,6-trichlorobenzoyl chloride / tetrahydrofuran / 0.08 h / 0 °C 3.2: 73 percent / DMAP / toluene; tetrahydrofuran / 0.5 h / 20 °C 4.1: 82 percent / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone / CH2Cl2; H2O / 2.5 h 5.1: 90 percent / trifluoroacetic acid / CH2Cl2 / 2.5 h / 20 °C View Scheme

1.1: 62 percent / 2 N NaOH / H2O / 1.5 h / Heating 2.1: Et3N; 2,4,6-trichlorobenzoyl chloride / tetrahydrofuran / 0.08 h / 0 °C 2.2: 73 percent / DMAP / toluene; tetrahydrofuran / 0.5 h / 20 °C 3.1: 82 percent / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone / CH2Cl2; H2O / 2.5 h 4.1: 90 percent / trifluoroacetic acid / CH2Cl2 / 2.5 h / 20 °C View Scheme

1.1: 93 percent / HF*pyridine / tetrahydrofuran / 36 h / 20 °C 2.1: 92 percent / Dess-Martin periodinane / CH2Cl2 / 1 h / 20 °C 3.1: 87 percent / TiCl4 / CH2Cl2 / 0.25 h / -78 °C 4.1: 89 percent / tetrabutylammonium fluoride / tetrahydrofuran / 0.17 h / 0 °C 5.1: 91 percent / imidazole / dimethylformamide / 36 h / 20 °C 6.1: 95 percent / Dess-Martin periodinane / CH2Cl2 / 2 h / 20 °C 7.1: 62 percent / 2 N NaOH / H2O / 1.5 h / Heating 8.1: Et3N; 2,4,6-trichlorobenzoyl chloride / tetrahydrofuran / 0.08 h / 0 °C 8.2: 73 percent / DMAP / toluene; tetrahydrofuran / 0.5 h / 20 °C 9.1: 82 percent / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone / CH2Cl2; H2O / 2.5 h 10.1: 90 percent / trifluoroacetic acid / CH2Cl2 / 2.5 h / 20 °C View Scheme

1.1: 89 percent / tetrabutylammonium fluoride / tetrahydrofuran / 0.17 h / 0 °C 2.1: 91 percent / imidazole / dimethylformamide / 36 h / 20 °C 3.1: 95 percent / Dess-Martin periodinane / CH2Cl2 / 2 h / 20 °C 4.1: 62 percent / 2 N NaOH / H2O / 1.5 h / Heating 5.1: Et3N; 2,4,6-trichlorobenzoyl chloride / tetrahydrofuran / 0.08 h / 0 °C 5.2: 73 percent / DMAP / toluene; tetrahydrofuran / 0.5 h / 20 °C 6.1: 82 percent / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone / CH2Cl2; H2O / 2.5 h 7.1: 90 percent / trifluoroacetic acid / CH2Cl2 / 2.5 h / 20 °C View Scheme

1.1: 89 percent / pyridine; DMAP / CH2Cl2 / 0 - 20 °C 2.1: 98 percent / 1,2-lutidine / CH2Cl2 / 0 - 20 °C 3.1: 94 percent / NaI / acetone / Heating 4.1: n-BuLi / tetrahydrofuran; hexamethylphosphoric acid triamide / -78 °C 4.2: 68 percent / tetrahydrofuran; hexamethylphosphoric acid triamide / -78 - -30 °C 5.1: DIBALH / CH2Cl2 / -30 °C 6.1: SO3*Py; TEA / CH2Cl2 / 0 °C 7.1: LDA; ZnCl2 / tetrahydrofuran / -78 - -40 °C 7.2: tetrahydrofuran / 1 h / -50 °C 8.1: 2,6-lutidine / CH2Cl2 / 0 - 20 °C 9.1: H2O; acetic acid / 20 °C 10.1: 2,4,6-trichlorobenzoyl chloride; TEA; DMAP / tetrahydrofuran; toluene / 1 h / 20 °C 10.2: 70 percent / H2SiF6 / 2-methyl-propan-2-ol; acetonitrile; CH2Cl2 / 24 h / 20 °C 11.1: 93 percent / oxalyl chloride; TEA; DMSO / CH2Cl2 / -78 °C 12.1: 60 percent / n-BuLi / tetrahydrofuran / -78 - 20 °C 13.1: 92 percent / TFA / CH2Cl2 / 1 h / 0 °C View Scheme

1.1: n-BuLi / tetrahydrofuran; hexamethylphosphoric acid triamide / -78 °C 1.2: 68 percent / tetrahydrofuran; hexamethylphosphoric acid triamide / -78 - -30 °C 2.1: DIBALH / CH2Cl2 / -30 °C 3.1: SO3*Py; TEA / CH2Cl2 / 0 °C 4.1: LDA; ZnCl2 / tetrahydrofuran / -78 - -40 °C 4.2: tetrahydrofuran / 1 h / -50 °C 5.1: 2,6-lutidine / CH2Cl2 / 0 - 20 °C 6.1: H2O; acetic acid / 20 °C 7.1: 2,4,6-trichlorobenzoyl chloride; TEA; DMAP / tetrahydrofuran; toluene / 1 h / 20 °C 7.2: 70 percent / H2SiF6 / 2-methyl-propan-2-ol; acetonitrile; CH2Cl2 / 24 h / 20 °C 8.1: 93 percent / oxalyl chloride; TEA; DMSO / CH2Cl2 / -78 °C 9.1: 60 percent / n-BuLi / tetrahydrofuran / -78 - 20 °C 10.1: 92 percent / TFA / CH2Cl2 / 1 h / 0 °C View Scheme

1.1: LDA; ZnCl2 / tetrahydrofuran / -78 - -40 °C 1.2: tetrahydrofuran / 1 h / -50 °C 2.1: 2,6-lutidine / CH2Cl2 / 0 - 20 °C 3.1: H2O; acetic acid / 20 °C 4.1: 2,4,6-trichlorobenzoyl chloride; TEA; DMAP / tetrahydrofuran; toluene / 1 h / 20 °C 4.2: 70 percent / H2SiF6 / 2-methyl-propan-2-ol; acetonitrile; CH2Cl2 / 24 h / 20 °C 5.1: 93 percent / oxalyl chloride; TEA; DMSO / CH2Cl2 / -78 °C 6.1: 60 percent / n-BuLi / tetrahydrofuran / -78 - 20 °C 7.1: 92 percent / TFA / CH2Cl2 / 1 h / 0 °C View Scheme

1.1: 98 percent / 1,2-lutidine / CH2Cl2 / 0 - 20 °C 2.1: 94 percent / NaI / acetone / Heating 3.1: n-BuLi / tetrahydrofuran; hexamethylphosphoric acid triamide / -78 °C 3.2: 68 percent / tetrahydrofuran; hexamethylphosphoric acid triamide / -78 - -30 °C 4.1: DIBALH / CH2Cl2 / -30 °C 5.1: SO3*Py; TEA / CH2Cl2 / 0 °C 6.1: LDA; ZnCl2 / tetrahydrofuran / -78 - -40 °C 6.2: tetrahydrofuran / 1 h / -50 °C 7.1: 2,6-lutidine / CH2Cl2 / 0 - 20 °C 8.1: H2O; acetic acid / 20 °C 9.1: 2,4,6-trichlorobenzoyl chloride; TEA; DMAP / tetrahydrofuran; toluene / 1 h / 20 °C 9.2: 70 percent / H2SiF6 / 2-methyl-propan-2-ol; acetonitrile; CH2Cl2 / 24 h / 20 °C 10.1: 93 percent / oxalyl chloride; TEA; DMSO / CH2Cl2 / -78 °C 11.1: 60 percent / n-BuLi / tetrahydrofuran / -78 - 20 °C 12.1: 92 percent / TFA / CH2Cl2 / 1 h / 0 °C View Scheme

1.1: 94 percent / NaI / acetone / Heating 2.1: n-BuLi / tetrahydrofuran; hexamethylphosphoric acid triamide / -78 °C 2.2: 68 percent / tetrahydrofuran; hexamethylphosphoric acid triamide / -78 - -30 °C 3.1: DIBALH / CH2Cl2 / -30 °C 4.1: SO3*Py; TEA / CH2Cl2 / 0 °C 5.1: LDA; ZnCl2 / tetrahydrofuran / -78 - -40 °C 5.2: tetrahydrofuran / 1 h / -50 °C 6.1: 2,6-lutidine / CH2Cl2 / 0 - 20 °C 7.1: H2O; acetic acid / 20 °C 8.1: 2,4,6-trichlorobenzoyl chloride; TEA; DMAP / tetrahydrofuran; toluene / 1 h / 20 °C 8.2: 70 percent / H2SiF6 / 2-methyl-propan-2-ol; acetonitrile; CH2Cl2 / 24 h / 20 °C 9.1: 93 percent / oxalyl chloride; TEA; DMSO / CH2Cl2 / -78 °C 10.1: 60 percent / n-BuLi / tetrahydrofuran / -78 - 20 °C 11.1: 92 percent / TFA / CH2Cl2 / 1 h / 0 °C View Scheme