1.1: 86 percent / 3 h / 160 °C 2.1: n-butyllithium / tetrahydrofuran; hexane / 1 h / -78 °C 2.2: 86 percent / tetrahydrofuran; hexane / 12 h / -78 - 20 °C 3.1: (1R)-(+)-pinene; BH3*DMS / tetrahydrofuran / 0.5 h / 20 °C 3.2: 78 percent / lithium hydroxide; sodium perborate / tetrahydrofuran; H2O / 2 h / 20 °C 4.1: 94 percent / oxalyl chloride; DMSO; triethylamine / CH2Cl2 / -78 - 0 °C 5.1: diisopropylamine; n-butyllithium / tetrahydrofuran; hexane / 1.25 h / -78 - -40 °C 5.2: 59 percent / ZnCl2 / tetrahydrofuran; hexane; diethyl ether / 0.25 h / -78 °C 6.1: pyridine / CH2Cl2 / 1 h / 0 °C 7.1: CH2Cl2 / 5 h / 20 °C 8.1: 0.67 g / acetic acid / tetrahydrofuran; H2O / 3 h / 0 °C 9.1: 72 percent / magnesium bromide; nitromethane; 1-butanethiol / diethyl ether / 1 h / 20 °C 10.1: 2,4,6-trichlorobenzoyl chloride; triethylamine / tetrahydrofuran / 1 h / 0 °C 10.2: 0.14 g / DMAP / toluene; tetrahydrofuran / 4 h / 20 °C 11.1: 92 percent / zinc; ammonium chloride / methanol / 0.33 h / Heating 12.1: 95 percent / hydrogen fluoride-pyridine / tetrahydrofuran / 16 h / 20 °C View Scheme

1.1: 99 percent / imidazole / dimethylformamide / 3 h / 0 - 20 °C 2.1: 18-crown-6; KHMDS / tetrahydrofuran / 1 h / -78 °C 2.2: 93 percent / tetrahydrofuran / 1 h / -78 °C 3.1: 65 percent / Na2HPO4; Na-Hg amalgam / methanol; tetrahydrofuran / -15 - 20 °C 4.1: 99 percent / CSA / methanol; CH2Cl2 / 5 h / 0 - 10 °C 5.1: Dess-Martin periodinane; pyridine / CH2Cl2 / 4 h / 20 °C 6.1: LDA / tetrahydrofuran / 1 h / -78 - -35 °C 6.2: tetrahydrofuran / 1.5 h / -95 - -80 °C 7.1: 99 percent / 2,6-lutidine / CH2Cl2 / 3 h / 0 °C 8.1: 87 percent / CSA / methanol; CH2Cl2 / 4 h / 0 °C 9.1: Dess-Martin periodinane; Py / CH2Cl2 / 2 h / 20 °C 10.1: 380 mg / NaClO2; NaH2PO4 / 2-methyl-propan-2-ol; various solvent(s); H2O / 3 h 11.1: 55 percent / TBAF / tetrahydrofuran / 10 h / 20 °C 12.1: 69 percent / N-ethyl-N'-(3-(dimethylamino)propyl)carbodiimide *HCl; DMAP; DMAP*HCl / CHCl3 / 17 h / Heating 13.1: 96 percent / HF*Py; Py / tetrahydrofuran / 36 h / 0 - 20 °C View Scheme

1.1: 99 percent / Dess-Martin periodinane; Py / CH2Cl2 / 2 h / 0 °C 2.1: LDA / tetrahydrofuran / 1 h / -78 - -35 °C 2.2: tetrahydrofuran / 1.5 h / -95 - -80 °C 3.1: 99 percent / 2,6-lutidine / CH2Cl2 / 3 h / 0 °C 4.1: 87 percent / CSA / methanol; CH2Cl2 / 4 h / 0 °C 5.1: Dess-Martin periodinane; Py / CH2Cl2 / 2 h / 20 °C 6.1: 380 mg / NaClO2; NaH2PO4 / 2-methyl-propan-2-ol; various solvent(s); H2O / 3 h 7.1: 55 percent / TBAF / tetrahydrofuran / 10 h / 20 °C 8.1: 69 percent / N-ethyl-N'-(3-(dimethylamino)propyl)carbodiimide *HCl; DMAP; DMAP*HCl / CHCl3 / 17 h / Heating 9.1: 96 percent / HF*Py; Py / tetrahydrofuran / 36 h / 0 - 20 °C View Scheme

1.1: 88 percent / TBAF / tetrahydrofuran / 10 h / 20 °C 2.1: 99 percent / imidazole / dimethylformamide / 3 h / 0 - 20 °C 3.1: 18-crown-6; KHMDS / tetrahydrofuran / 1 h / -78 °C 3.2: 93 percent / tetrahydrofuran / 1 h / -78 °C 4.1: 65 percent / Na2HPO4; Na-Hg amalgam / methanol; tetrahydrofuran / -15 - 20 °C 5.1: 99 percent / CSA / methanol; CH2Cl2 / 5 h / 0 - 10 °C 6.1: Dess-Martin periodinane; pyridine / CH2Cl2 / 4 h / 20 °C 7.1: LDA / tetrahydrofuran / 1 h / -78 - -35 °C 7.2: tetrahydrofuran / 1.5 h / -95 - -80 °C 8.1: 99 percent / 2,6-lutidine / CH2Cl2 / 3 h / 0 °C 9.1: 87 percent / CSA / methanol; CH2Cl2 / 4 h / 0 °C 10.1: Dess-Martin periodinane; Py / CH2Cl2 / 2 h / 20 °C 11.1: 380 mg / NaClO2; NaH2PO4 / 2-methyl-propan-2-ol; various solvent(s); H2O / 3 h 12.1: 55 percent / TBAF / tetrahydrofuran / 10 h / 20 °C 13.1: 69 percent / N-ethyl-N'-(3-(dimethylamino)propyl)carbodiimide *HCl; DMAP; DMAP*HCl / CHCl3 / 17 h / Heating 14.1: 96 percent / HF*Py; Py / tetrahydrofuran / 36 h / 0 - 20 °C View Scheme

1.1: diisobutylaluminium hydride / tetrahydrofuran / 5.25 h / 0 - 20 °C 2.1: tin tetrabromide / dichloromethane / 0.08 h / -78 °C 2.2: 0.5 h / -78 °C 3.1: pyridine / dichloromethane / 16 h 4.1: tri-n-butyl-tin hydride; 2,2'-azo-bisisobutyronitrile / toluene / 1.5 h / |Inert atmosphere; |Reflux 5.1: 2,3-dicyano-5,6-dichloro-p-benzoquinone; water / dichloromethane 6.1: pyridine / 5 h 7.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 4 h / 0 - 20 °C 8.1: Dess-Martin periodane / dichloromethane / 0.5 h / 20 °C 9.1: diethyl ether / 1 h / -78 °C 10.1: Dess-Martin periodane / dichloromethane / 0.5 h / 20 °C 11.1: n-butyllithium / tetrahydrofuran; hexane / 1 h / -78 °C 11.2: 15 h / 20 °C 12.1: diisobutylaluminium hydride / tetrahydrofuran / 3.25 h / 0 - 20 °C 13.1: Dess-Martin periodane / dichloromethane / 0.5 h / 20 °C 14.1: lithium diisopropyl amide; n-butyllithium / tetrahydrofuran; hexane / 1.5 h / -78 - 40 °C 14.2: 0.03 h / -78 °C 15.1: 2,6-dimethylpyridine / dichloromethane / 6 h / 0 °C 16.1: dichloro-acetic acid / dichloromethane / 2 h / 20 °C 17.1: Dess-Martin periodane / dichloromethane / 0.5 h / 20 °C 18.1: sodium chlorite; sodium dihydrogenphosphate; 1,1,2,2-tetramethylethylene / tetrahydrofuran; water; tert-butyl alcohol / 1 h / 20 °C 19.1: potassium carbonate; MgBr2(Et2O); butane-1-thiol / diethyl ether / 2 h / 20 °C 20.1: triethylamine; 2,4,6-trichlorobenzoyl chloride / tetrahydrofuran / 0.75 h / 0 °C 20.2: 5 h / 75 °C 21.1: trifluoroacetic acid / dichloromethane / 6 h / 0 °C View Scheme

1.1: tin tetrabromide / dichloromethane / 0.08 h / -78 °C 1.2: 0.5 h / -78 °C 2.1: pyridine / dichloromethane / 16 h 3.1: tri-n-butyl-tin hydride; 2,2'-azo-bisisobutyronitrile / toluene / 1.5 h / |Inert atmosphere; |Reflux 4.1: 2,3-dicyano-5,6-dichloro-p-benzoquinone; water / dichloromethane 5.1: pyridine / 5 h 6.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 4 h / 0 - 20 °C 7.1: Dess-Martin periodane / dichloromethane / 0.5 h / 20 °C 8.1: diethyl ether / 1 h / -78 °C 9.1: Dess-Martin periodane / dichloromethane / 0.5 h / 20 °C 10.1: n-butyllithium / tetrahydrofuran; hexane / 1 h / -78 °C 10.2: 15 h / 20 °C 11.1: diisobutylaluminium hydride / tetrahydrofuran / 3.25 h / 0 - 20 °C 12.1: Dess-Martin periodane / dichloromethane / 0.5 h / 20 °C 13.1: lithium diisopropyl amide; n-butyllithium / tetrahydrofuran; hexane / 1.5 h / -78 - 40 °C 13.2: 0.03 h / -78 °C 14.1: 2,6-dimethylpyridine / dichloromethane / 6 h / 0 °C 15.1: dichloro-acetic acid / dichloromethane / 2 h / 20 °C 16.1: Dess-Martin periodane / dichloromethane / 0.5 h / 20 °C 17.1: sodium chlorite; sodium dihydrogenphosphate; 1,1,2,2-tetramethylethylene / tetrahydrofuran; water; tert-butyl alcohol / 1 h / 20 °C 18.1: potassium carbonate; MgBr2(Et2O); butane-1-thiol / diethyl ether / 2 h / 20 °C 19.1: triethylamine; 2,4,6-trichlorobenzoyl chloride / tetrahydrofuran / 0.75 h / 0 °C 19.2: 5 h / 75 °C 20.1: trifluoroacetic acid / dichloromethane / 6 h / 0 °C View Scheme

1.1: Tebbe's reagent / toluene / 0.5 h / 0 - 20 °C 2.1: Dess-Martin periodane / dichloromethane / 0.5 h 3.1: cerium(III) chloride / tetrahydrofuran / 0.5 h / 0 °C 3.2: 1 h / 0 °C 4.1: borane-THF / tetrahydrofuran / 6 h / 0 - 20 °C 4.2: 0.5 h 5.1: N-ethyl-N,N-diisopropylamine; 4-(N,N-dimethlyamino)pyridine / dichloromethane / 16 h / 20 °C 6.1: Dess-Martin periodane / dichloromethane / 0.5 h 7.1: lithium diisopropyl amide; n-butyllithium / tetrahydrofuran; hexane / 1.5 h / -78 - 40 °C 7.2: 0.03 h / -78 °C 8.1: 2,6-dimethylpyridine / dichloromethane / 6 h / 0 °C 9.1: dichloro-acetic acid / dichloromethane / 2 h / 20 °C 10.1: Dess-Martin periodane / dichloromethane / 0.5 h / 20 °C 11.1: sodium chlorite; sodium dihydrogenphosphate; 1,1,2,2-tetramethylethylene / tetrahydrofuran; water; tert-butyl alcohol / 1 h / 20 °C 12.1: potassium carbonate; MgBr2(Et2O); butane-1-thiol / diethyl ether / 2 h / 20 °C 13.1: triethylamine; 2,4,6-trichlorobenzoyl chloride / tetrahydrofuran / 0.75 h / 0 °C 13.2: 5 h / 75 °C 14.1: trifluoroacetic acid / dichloromethane / 6 h / 0 °C View Scheme

1.1: Dess-Martin periodane / dichloromethane / 0.5 h 2.1: cerium(III) chloride / tetrahydrofuran / 0.5 h / 0 °C 2.2: 1 h / 0 °C 3.1: borane-THF / tetrahydrofuran / 6 h / 0 - 20 °C 3.2: 0.5 h 4.1: N-ethyl-N,N-diisopropylamine; 4-(N,N-dimethlyamino)pyridine / dichloromethane / 16 h / 20 °C 5.1: Dess-Martin periodane / dichloromethane / 0.5 h 6.1: lithium diisopropyl amide; n-butyllithium / tetrahydrofuran; hexane / 1.5 h / -78 - 40 °C 6.2: 0.03 h / -78 °C 7.1: 2,6-dimethylpyridine / dichloromethane / 6 h / 0 °C 8.1: dichloro-acetic acid / dichloromethane / 2 h / 20 °C 9.1: Dess-Martin periodane / dichloromethane / 0.5 h / 20 °C 10.1: sodium chlorite; sodium dihydrogenphosphate; 1,1,2,2-tetramethylethylene / tetrahydrofuran; water; tert-butyl alcohol / 1 h / 20 °C 11.1: potassium carbonate; MgBr2(Et2O); butane-1-thiol / diethyl ether / 2 h / 20 °C 12.1: triethylamine; 2,4,6-trichlorobenzoyl chloride / tetrahydrofuran / 0.75 h / 0 °C 12.2: 5 h / 75 °C 13.1: trifluoroacetic acid / dichloromethane / 6 h / 0 °C View Scheme

1.1: borane-THF / tetrahydrofuran / 6 h / 0 - 20 °C 1.2: 0.5 h 2.1: N-ethyl-N,N-diisopropylamine; 4-(N,N-dimethlyamino)pyridine / dichloromethane / 16 h / 20 °C 3.1: Dess-Martin periodane / dichloromethane / 0.5 h 4.1: lithium diisopropyl amide; n-butyllithium / tetrahydrofuran; hexane / 1.5 h / -78 - 40 °C 4.2: 0.03 h / -78 °C 5.1: 2,6-dimethylpyridine / dichloromethane / 6 h / 0 °C 6.1: dichloro-acetic acid / dichloromethane / 2 h / 20 °C 7.1: Dess-Martin periodane / dichloromethane / 0.5 h / 20 °C 8.1: sodium chlorite; sodium dihydrogenphosphate; 1,1,2,2-tetramethylethylene / tetrahydrofuran; water; tert-butyl alcohol / 1 h / 20 °C 9.1: potassium carbonate; MgBr2(Et2O); butane-1-thiol / diethyl ether / 2 h / 20 °C 10.1: triethylamine; 2,4,6-trichlorobenzoyl chloride / tetrahydrofuran / 0.75 h / 0 °C 10.2: 5 h / 75 °C 11.1: trifluoroacetic acid / dichloromethane / 6 h / 0 °C View Scheme

1.1: TsOH; MeOH / CH2Cl2 2.1: Et3N; DMAP / CH2Cl2 3.1: Pd(OAc)2; DPPP; Bu4NOAc / 1 h / 20 °C 3.2: NaBH4 3.3: NaOMe; MeOH 4.1: (COCl)2; DMSO; Et3N 5.1: tetrahydrofuran / -78 - 20 °C 6.1: (COCl)2; DMSO; Et3N / CH2Cl2 7.1: tBuOK / tetrahydrofuran 7.2: 75 percent / tetrahydrofuran / 4 h / -30 - 20 °C 8.1: AcOH; H2O / tetrahydrofuran / 24 h / 20 °C 9.1: NaBH4 / methanol 10.1: CBr4; PPh3 / acetonitrile / 0 °C 10.2: 91 percent / 2,6-di-tert-butyl-4-methylpyridine / acetonitrile / -40 °C 11.1: tetrahydrofuran / -78 °C 12.1: LiHMDS / tetrahydrofuran / -78 °C 12.2: 80 percent / tetrahydrofuran 13.1: TMSOTf; collidine / CH2Cl2 / 1 h / 0 °C 13.2: 85 percent / nBu4NF / tetrahydrofuran 14.1: 2,4,6-trichlorobenzoyl chloride; Et3N / tetrahydrofuran / 1 h / 20 °C 14.2: 60 percent / DMAP / toluene / 80 °C 15.1: 86 percent / TFA / CH2Cl2 / 0 °C 16.1: 71 percent / 2,4,6-triisopropylbenzenesulfonyl hydrazide; Et3N / diethyl ether / 39 °C View Scheme