反应详情

To a solution of (S)-3-[(2S,3R,4R,5S)-5-(N-benzyloxycarbonyl-L-leucyl)amino-2,3,4,6-tetrahydroxyhexanoyl]amino-3-phenylpropionic acid (295 mg) and 1,8-diazabicyclo[5.4.0]undec-7-ene (0.082 ml) in dimethylformamide (2 ml) was added a solution of iodomethyl pivalate (139 mg) in dimethylformamide (1 ml) and the mixture was stirred at room temperature for 1 hour. After addition of water, the reaction mixture was extracted with ethyl acetate and the extract was washed with 10% aqueous citric acid solution, saturated aqueous sodium hydrogencarbonate solution andsaturated brine respectively. The organic solution was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was passed through a column of silica gel, followed by elution with ethyl acetate:methanol (10:1). The effective fractions were combined and concentrated under reduced pressure. Recrystallization from chloroform provided the title compound (160 mg).

1. extractionthe reaction mixture was extracted with ethyl acetate
2. washthe extract was washed with 10% aqueous citric acid solution, saturated aqueous sodium hydrogencarbonate solution
3. dry with materialThe organic solution was dried over anhydrous sodium sulfate
4. concentrationconcentrated under reduced pressure
5. washfollowed by elution with ethyl acetate:methanol (10:1)
6. concentrationconcentrated under reduced pressure
7. customRecrystallization from chloroform