乙基4-氧代四氢-2H-吡喃-3-羧酸盐

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: First, 3-ethoxycarbonyl-tetrahydro-4H-pyran4-one was synthesized referring the process described in Japan Laid-Open Patent Publication No. 32080/90. Then this ester was fluorinated in the same manner as in Example 4 to prepare 3-ethoxycarbony-3-fluoro-tetrahydro-4H-pyran-4-one which was then reduced in the same manner as in the same example to prepare 3-ethoxycarbonyl-3-fluoro-4-hydroxytetrahydro-4H-pyran.

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: First, 3-ethoxycarbonyl-tetrahydro-4H-pyran4-one was synthesized referring the process described in Japan Laid-Open Patent Publication No. 32080/90. Then this ester was fluorinated in the same manner as in Example 4 to prepare 3-ethoxycarbony-3-fluoro-tetrahydro-4H-pyran-4-one which was then reduced in the same manner as in the same example to prepare 3-ethoxycarbonyl-3-fluoro-4-hydroxytetrahydro-4H-pyran.

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: First, 3-ethoxycarbonyl-tetrahydro-4H-pyran4-one was synthesized referring the process described in Japan Laid-Open Patent Publication No. 32080/90. Then this ester was fluorinated in the same manner as in Example 4 to prepare 3-ethoxycarbony-3-fluoro-tetrahydro-4H-pyran-4-one which was then reduced in the same manner as in the same example to prepare 3-ethoxycarbonyl-3-fluoro-4-hydroxytetrahydro-4H-pyran.

反应条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Lithium diisopropylamide (1.14 mol/l solution in n-hexane/tetrahydrofuran, 2.5 ml) was added dropwise to a solution of tetrahydro-4H-pyran-4-one (260 mg) in tetrahydrofuran (13 ml) at −78° C., and the mixture was stirred for one hour while warming to 0° C. The reaction solution was cooled to −78° C. again, hexamethylphosphoric triamide (452 μl) was added and subsequently ethyl cyanoformate (280 μl) was added at the same temperature. The mixture was stirred over one hour while warming to 0° C. The reaction solution was separated by adding distilled water and ethyl acetate. The resulting organic layer was washed with brine and dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure. The resulting residue was purified by silica gel column chromatography (developed with ethyl acetate-hexane) to give the title compound (210 mg). The reaction solution was cooled to −78° C. again The mixture was stirred over one hour while warming to 0° C The reaction solution was separated by adding distilled water and ethyl acetate The resulting organic layer was washed with brine dried over anhydrous sodium sulfate The solvent was evaporated under reduced pressure The resulting residue was purified by silica gel column chromatography (developed with ethyl acetate-hexane)

反应条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Lithium diisopropylamide (1.14 mol/l solution in n-hexane/tetrahydrofuran, 2.5 ml) was added dropwise to a solution of tetrahydro-4H-pyran-4-one (260 mg) in tetrahydrofuran (13 ml) at −78° C., and the mixture was stirred for one hour while warming to 0° C. The reaction solution was cooled to −78° C. again, hexamethylphosphoric triamide (452 μl) was added and subsequently ethyl cyanoformate (280 μl) was added at the same temperature. The mixture was stirred over one hour while warming to 0° C. The reaction solution was separated by adding distilled water and ethyl acetate. The resulting organic layer was washed with brine and dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure. The resulting residue was purified by silica gel column chromatography (developed with ethyl acetate-hexane) to give the title compound (210 mg). The reaction solution was cooled to −78° C. again The mixture was stirred over one hour while warming to 0° C The reaction solution was separated by adding distilled water and ethyl acetate The resulting organic layer was washed with brine dried over anhydrous sodium sulfate The solvent was evaporated under reduced pressure The resulting residue was purified by silica gel column chromatography (developed with ethyl acetate-hexane)

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: First, 3-ethoxycarbonyl-tetrahydro-4H-pyran4-one was synthesized referring the process described in Japan Laid-Open Patent Publication No. 32080/90. Then this ester was fluorinated in the same manner as in Example 4 to prepare 3-ethoxycarbony-3-fluoro-tetrahydro-4H-pyran-4-one which was then reduced in the same manner as in the same example to prepare 3-ethoxycarbonyl-3-fluoro-4-hydroxytetrahydro-4H-pyran.