Amberlyst 15 in methanol T=45°C; 1 h; Yields of byproduct given. Title compound not separated from byproducts;

methanol; cesium fluoride T=20°C; 3 h;

1: 33 percent / Et3N, ClCOOEt / tetrahydrofuran / 0.08 h / 0 °C 2: 81 percent / Amberlyst 15 / methanol / 1 h / 45 °C View Scheme

1: NH2OH / methanol / 2 h / 20 °C 2: 65 mg / DDQ / dioxane / 20 °C View Scheme

1.1: InI / (1,1'-bis(diphenylphosphino)ferrocene)palladium(II) dichloride / N,N,N',N',N'',N''-hexamethylphosphoric triamide; tetrahydrofuran / 1 h / 0 °C 2.1: trifluoroacetic acid / 48 h / 25 °C 3.1: 2,2,6,6-tetramethylpiperidinyl-lithium / tetrahydrofuran / 0.5 h / -78 °C 3.2: 6.5 h / -78 - 0 °C 4.1: (-)-Ipc2BH / tetrahydrofuran / 2 h / 0 °C 4.2: 1 h / 0 - 20 °C 5.1: lithium hydroxide hydrate / methanol / 24 h / 45 °C 5.2: pH 4 6.1: 2,3-dicyano-5,6-dichloro-p-benzoquinone / dichloromethane; water / 0.17 h / 0 °C 7.1: chloroformic acid ethyl ester; triethylamine / dichloromethane / 2 h / 0 °C 7.2: 2.5 h / 0 - 20 °C 8.1: cesium fluoride; methanol / 3 h / 20 °C View Scheme

1: CH2Cl2 / 6 h / Heating 2: 76 percent / DIBAL-H / toluene; hexane / 0.5 h / -78 °C 3: Et3N, SO3-C5H5N, DMSO / Ambient temperature 4: CH2Cl2 / 24 h / Heating 5: aq. LiOH / methanol / 12 h / 45 °C 6: 88 percent / DDQ / dioxane / 0.08 h / Ambient temperature 7: Et3N, ClCOOEt / tetrahydrofuran / 0.08 h / 0 °C 8: Amberlyst 15 / methanol / 1 h / 45 °C View Scheme

1: 90 percent / PPTS / 3 h / Ambient temperature 2: 80 percent / (n-Bu)4NF / tetrahydrofuran / 4 h / 40 °C 3: Et3N, SO3-C5H5N, DMSO / Ambient temperature 4: CH2Cl2 / 6 h / Heating 5: 76 percent / DIBAL-H / toluene; hexane / 0.5 h / -78 °C 6: Et3N, SO3-C5H5N, DMSO / Ambient temperature 7: CH2Cl2 / 24 h / Heating 8: aq. LiOH / methanol / 12 h / 45 °C 9: 88 percent / DDQ / dioxane / 0.08 h / Ambient temperature 10: Et3N, ClCOOEt / tetrahydrofuran / 0.08 h / 0 °C 11: Amberlyst 15 / methanol / 1 h / 45 °C View Scheme

1: Et3N, SO3-C5H5N, DMSO / 0.08 h / Ambient temperature 2: CH2Cl2 / 6 h / Heating 3: 89 percent / DIBAL-H / toluene; hexane / 0.5 h / -78 °C 4: Et3N, SO3-C5H5N, DMSO / Ambient temperature 5: CH2Cl2 / 24 h / Heating 6: 80 percent / aq. LiOH / methanol / 12 h / 45 °C 7: 34 percent / DDQ / dioxane / 0.08 h / Ambient temperature 8: 33 percent / Et3N, ClCOOEt / tetrahydrofuran / 0.08 h / 0 °C 9: 81 percent / Amberlyst 15 / methanol / 1 h / 45 °C View Scheme

1: Et3N, SO3-C5H5N, DMSO / Ambient temperature 2: CH2Cl2 / 24 h / Heating 3: 80 percent / aq. LiOH / methanol / 12 h / 45 °C 4: 34 percent / DDQ / dioxane / 0.08 h / Ambient temperature 5: 33 percent / Et3N, ClCOOEt / tetrahydrofuran / 0.08 h / 0 °C 6: 81 percent / Amberlyst 15 / methanol / 1 h / 45 °C View Scheme

1: Et3N, ClCOOEt / tetrahydrofuran / 0.08 h / 0 °C 2: Amberlyst 15 / methanol / 1 h / 45 °C View Scheme