反应详情

To a solution of 838 mg of 2-benzyloxycarbonylamino-5-oxo-2-tetrahydrofurancarboxylic acid in 5 ml of dimethylformamide was added 120 mg of sodium hydride (60% oil) while stirring under ice-cooling. To the mixture was then added 648 mg of 4-nitrobenzyl bromide, followed by stirring at room temperature for 2.5 hours. To the reaction mixture was added a saturated aqueous solution of sodium hydrogencarbonate, which was subjected to extraction with ethyl acetate. The organic layer was washed with a saturated aqueous saline solution and then dried (MgSO4), followed by distilling off the solvent. The residue was subjected to a silica gel column chromatography, eluting with hexane-ethyl acetate (1:1). Fractions containing the end product were combined and concentrated under reduced pressure to give 687 mg of 4-nitrobenzyl 2-benzyloxycarbonylamino-5-oxo-2-tetrahydrofurancarboxylate as colorless crystals, m.p. 127°-127.5° C.

1. temperaturecooling
2. stirringby stirring at room temperature for 2.5 hours
3. extractionwas subjected to extraction with ethyl acetate
4. washThe organic layer was washed with a saturated aqueous saline solution
5. dry with materialdried (MgSO4)
6. distillationby distilling off the solvent
7. washeluting with hexane-ethyl acetate (1:1)
8. additionFractions containing the end product
9. concentrationconcentrated under reduced pressure