反应详情

688 mg of potassium nitrite and 428 mg of 18-crown 6-ether was added to 701 mg of (1R,2R,3R,5R,6R)-2-azido-6-fluoro-3-trifluoromethanesulfonyloxy-bicyclo[3.1.0]hexane-2,6-dicarboxylic acid diethyl ester dissolved in 6.9 mL of N,N-dimethylformamide, and the mixture was stirred for 1.5 days at room temperature and further stirred for 3.5 days at 45° C., under a nitrogen atmosphere. Water was added thereto, and the mixture was extracted twice with ethyl acetate. The organic layers were combined, washed with a saturated aqueous solution of sodium chloride, and then dried over anhydrous sodium sulfate. After the desiccant was filtered off, the filtrate was concentrated under reduced pressure, and the residue was purified by column chromatography (silica gel: Wako gel C200, eluent: hexane-ethyl acetate=5:1), thereby yielding 388 mg of (1R,2R,3S,5R,6R)-2-azido-6-fluoro-3-hydroxy-bicyclo[3.1.0]hexane-2,6-dicarboxylic acid 2,6-diethyl ester.

1. stirringfurther stirred for 3.5 days at 45° C., under a nitrogen atmosphere
2. extractionthe mixture was extracted twice with ethyl acetate
3. washwashed with a saturated aqueous solution of sodium chloride
4. dry with materialdried over anhydrous sodium sulfate
5. filtrationAfter the desiccant was filtered off
6. concentrationthe filtrate was concentrated under reduced pressure
7. customthe residue was purified by column chromatography (silica gel: Wako gel C200, eluent: hexane-ethyl acetate=5:1)