1: lithium tri-tert-butoxyaluminohydride / tetrahydrofuran / 1) -78 deg C, 5 min, 2) 0 deg C, 15 min 2: 1.26 g / Et3N, 4-DMAP / CH2Cl2 / 1) 0 deg C, 2 h, 2) 25 deg C, 10 h 3: 1) LDA / 1) THF, -78 deg C, 15 min; -78 deg C -> -40 deg C, 1 h, 2) THF, -78 deg C, 15 min 4: 96 percent / 2,6-lutidine / CH2Cl2 / 2 h / 0 °C 5: 85 percent / camphorsulfonic acid / CH2Cl2; methanol / 0.5 h / 0 - 25 °C View Scheme

1: 93 percent / NaClO2, 2-methyl-2-butene, NaH2PO4 / 2-methyl-propan-2-ol; tetrahydrofuran; H2O / 4 h / Ambient temperature 2: 1) LDA / 1) THF, -78 deg C, 15 min; -40 deg C, 0.5 h, 2) THF, -78 deg C, 15 min 3: 2,6-lutidine / CH2Cl2 / 2 h / 0 °C 4: 1.1 g / K2CO3 / methanol / 0.25 h / 25 °C 5: 78 percent / TBAF / tetrahydrofuran / 8 h / 25 °C 6: 1) Et3N, 2,4,6-trichlorobenzoyl chloride, 2) 4-DMAP / 1) THF, 0 deg C, 15 min, 2) toluene, 25 deg C, 0.5 h 7: 92 percent / CF3CO2H / CH2Cl2 / 1) -20 deg C -> 0 deg C, 2) 0 deg C, 1 h 8: 65 percent / Na2EDTA, 1,1,1-trifluoroacetone, Oxone, NaHCO3 / acetonitrile; H2O / 0 °C View Scheme

1: lithium tri-tert-butoxyaluminohydride / tetrahydrofuran / 1) -78 deg C, 5 min, 2) 0 deg C, 15 min 2: 1.26 g / Et3N, 4-DMAP / CH2Cl2 / 1) 0 deg C, 2 h, 2) 25 deg C, 10 h 3: 1) LDA / 1) THF, -78 deg C, 15 min; -78 deg C -> -40 deg C, 1 h, 2) THF, -78 deg C, 15 min 4: 96 percent / 2,6-lutidine / CH2Cl2 / 2 h / 0 °C 5: 85 percent / camphorsulfonic acid / CH2Cl2; methanol / 0.5 h / 0 - 25 °C 6: 1) (COCl)2, DMSO, 2) Et3N / 1) CH2Cl2, -78 deg C, 30 min, 2) CH2Cl2, -78 deg C -> 0 deg C, 30 min 7: 90 percent / NaClO2, isobutylene, NaH2PO4 / 2-methyl-propan-2-ol; H2O; tetrahydrofuran / 1 h / Ambient temperature 8: 73 percent / TBAF / tetrahydrofuran / 8 h / 25 °C 9: 1) Et3N, 2,4,6-trichlorobenzoyl chloride, 2) 4-DMAP / 1) THF, 25 deg C, 15 min, 2) toluene, 25 deg C, 12 h 10: 91 percent / CF3CO2H / CH2Cl2 / 1) -20 deg C -> 0 deg C, 2) 0 deg C, 1 h 11: Na2EDTA, 1,1,1-trifluoroacetone, Oxone, NaHCO3 / acetonitrile; H2O / 0 °C View Scheme

1: lithium tri-tert-butoxyaluminohydride / tetrahydrofuran / 1) -78 deg C, 5 min, 2) 0 deg C, 15 min 2: 1.26 g / Et3N, 4-DMAP / CH2Cl2 / 1) 0 deg C, 2 h, 2) 25 deg C, 10 h 3: 1) LDA / 1) THF, -78 deg C, 15 min; -78 deg C -> -40 deg C, 1 h, 2) THF, -78 deg C, 15 min 4: 96 percent / 2,6-lutidine / CH2Cl2 / 2 h / 0 °C 5: 85 percent / camphorsulfonic acid / CH2Cl2; methanol / 0.5 h / 0 - 25 °C 6: 1) (COCl)2, DMSO, 2) Et3N / 1) CH2Cl2, -78 deg C, 30 min, 2) CH2Cl2, -78 deg C -> 0 deg C, 30 min 7: 90 percent / NaClO2, isobutylene, NaH2PO4 / 2-methyl-propan-2-ol; H2O; tetrahydrofuran / 1 h / Ambient temperature 8: 73 percent / TBAF / tetrahydrofuran / 8 h / 25 °C 9: 1) Et3N, 2,4,6-trichlorobenzoyl chloride, 2) 4-DMAP / 1) THF, 25 deg C, 15 min, 2) toluene, 25 deg C, 12 h 10: 91 percent / CF3CO2H / CH2Cl2 / 1) -20 deg C -> 0 deg C, 2) 0 deg C, 1 h View Scheme

1: lithium tri-tert-butoxyaluminohydride / tetrahydrofuran / 1) -78 deg C, 5 min, 2) 0 deg C, 15 min 2: 1.26 g / Et3N, 4-DMAP / CH2Cl2 / 1) 0 deg C, 2 h, 2) 25 deg C, 10 h 3: 1) LDA / 1) THF, -78 deg C, 15 min; -78 deg C -> -40 deg C, 1 h, 2) THF, -78 deg C, 15 min 4: 96 percent / 2,6-lutidine / CH2Cl2 / 2 h / 0 °C View Scheme

1: lithium tri-tert-butoxyaluminohydride / tetrahydrofuran / 1) -78 deg C, 5 min, 2) 0 deg C, 15 min 2: 1.26 g / Et3N, 4-DMAP / CH2Cl2 / 1) 0 deg C, 2 h, 2) 25 deg C, 10 h 3: 1) LDA / 1) THF, -78 deg C, 15 min; -78 deg C -> -40 deg C, 1 h, 2) THF, -78 deg C, 15 min 4: 96 percent / 2,6-lutidine / CH2Cl2 / 2 h / 0 °C 5: 85 percent / camphorsulfonic acid / CH2Cl2; methanol / 0.5 h / 0 - 25 °C 6: 1) (COCl)2, DMSO, 2) Et3N / 1) CH2Cl2, -78 deg C, 30 min, 2) CH2Cl2, -78 deg C -> 0 deg C, 30 min 7: 90 percent / NaClO2, isobutylene, NaH2PO4 / 2-methyl-propan-2-ol; H2O; tetrahydrofuran / 1 h / Ambient temperature View Scheme

1: lithium tri-tert-butoxyaluminohydride / tetrahydrofuran / 1) -78 deg C, 5 min, 2) 0 deg C, 15 min 2: 1.26 g / Et3N, 4-DMAP / CH2Cl2 / 1) 0 deg C, 2 h, 2) 25 deg C, 10 h 3: 1) LDA / 1) THF, -78 deg C, 15 min; -78 deg C -> -40 deg C, 1 h, 2) THF, -78 deg C, 15 min View Scheme

1: 93 percent / NaClO2, 2-methyl-2-butene, NaH2PO4 / 2-methyl-propan-2-ol; tetrahydrofuran; H2O / 4 h / Ambient temperature 2: 1) LDA / 1) THF, -78 deg C, 15 min; -40 deg C, 0.5 h, 2) THF, -78 deg C, 15 min 3: 2,6-lutidine / CH2Cl2 / 2 h / 0 °C 4: 1.1 g / K2CO3 / methanol / 0.25 h / 25 °C 5: 78 percent / TBAF / tetrahydrofuran / 8 h / 25 °C 6: 1) Et3N, 2,4,6-trichlorobenzoyl chloride, 2) 4-DMAP / 1) THF, 0 deg C, 15 min, 2) toluene, 25 deg C, 0.5 h 7: 92 percent / CF3CO2H / CH2Cl2 / 1) -20 deg C -> 0 deg C, 2) 0 deg C, 1 h View Scheme

1.1: sodium tetrahydroborate / dichloromethane; ethanol / 2 h / -78 °C / |Inert atmosphere 1.2: 22 °C / |Inert atmosphere 2.1: 1H-imidazole / dichloromethane / 14 h / 22 °C / |Inert atmosphere 3.1: diisopropylamine; n-butyllithium / tetrahydrofuran; hexane / 1.5 h / -78 - 0 °C / |Inert atmosphere 3.2: 0.25 h / -78 °C / |Inert atmosphere 4.1: 2,6-dimethylpyridine / tetrahydrofuran / 0.5 h / -50 °C / |Inert atmosphere 5.1: oxalyl dichloride / dichloromethane; dimethyl sulfoxide / 1 h / -78 - -40 °C / |Inert atmosphere 5.2: 0 - 22 °C / |Inert atmosphere 6.1: sodium dihydrogen phosphate monohydrate; 2-methyl-but-2-ene; sodium chlorite / water; tert-butyl alcohol / 3 h / 22 °C / |Inert atmosphere 7.1: 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; 4-(N,N-dimethlyamino)pyridine / dichloromethane / 16 h / 22 °C / |Inert atmosphere 8.1: C52H67Cl2NOW / benzene; toluene / 2.5 h / 22 °C / 1 Torr / |Inert atmosphere; |Glovebox 9.1: pyridine hydrogenfluoride / tetrahydrofuran / 36 h / 22 °C / |Inert atmosphere View Scheme

1: (3S)-3-(tert-butyl-dimethyl-silanyloxy)-4,4-dimethyl-5-oxo-heptanal With sodium tetrahydroborate in ethanol; dichloromethane T=-78°C; 1 h; 2: tert-butyldimethylsilyl chloride With 1H-imidazole in dichloromethane T=20°C; 16 h; Further stages.;