反应详情

To a mixture of (S)-3-[(2S,3R,4R,5S)-2,3,4,6-tetrahydroxy-5-(L-leucyl)aminohexanoyl]amino-3-phenylpropionic acid (Compound 3) (2.28 g) and 0.2N aqueous sodium hydroxide solution (25 ml) were added benzyl chloroformate (0.714 ml) and 1N aqueous sodium hydroxide solution at 0° C. After stirring at room temperature for 3 hours, the mixture was washed with diethylether and acidified with 1N hydrochloric acid (20 ml). The aqueous solution was extracted with ethyl acetate and the organic layer was washed with saturated brine and dried over anhydrous sodium sulfate. Removal of the organic solvent gave a residue, which was recrystallized from diethylether-hexane to afford the title compound(1.51 g)

1. washthe mixture was washed with diethylether
2. extractionThe aqueous solution was extracted with ethyl acetate
3. washthe organic layer was washed with saturated brine
4. dry with materialdried over anhydrous sodium sulfate
5. customRemoval of the organic solvent
6. customgave a residue, which
7. customwas recrystallized from diethylether-hexane