反应详情

A solution of the title G compound, (2R)-(t-butyloxycarbonylamino)-5-(1,3-dioxo-1,3-dihydroisoindol-2-yl)pentanoic acid t-butyl ester (4.83 g, 11.55 mmol) in 18 mL of dichloromethane is treated with trifluoroacetic acid (TFA; 6.00 mL, 78 mmol) at 0° C. After stirring for 1 h at this temperature, the solution is concentrated under reduced pressure without heating, and the residue is partitioned between 100 mL of ethyl acetate and 50 mL of 1M aqueous NaHCO3. The organic phase is dried over anhydrous Na2SO4 and concentrated. Chomatography on silica gel (eluant; 1/1—ethyl acetate/hexane) affords 2.58 g (70%) of (2R)-amino-5-(1,3-dioxo-1,3-dihydroisoindol-2-yl)pentanoic acid t-butyl ester as a colorless foam: NMR(CDCl3) 1.46 (s, 9H), 1.80-2.06 (m, 4H), 3.73 (t, 2H, J=6.2), 3.97 (t, 1H, J=6.3), 7.68-7.71 (m, 2H), 7.82-7.85 (m, 2H).

1. concentrationthe solution is concentrated under reduced pressure
2. temperaturewithout heating
3. customthe residue is partitioned between 100 mL of ethyl acetate and 50 mL of 1M aqueous NaHCO3
4. dry with materialThe organic phase is dried over anhydrous Na2SO4
5. concentrationconcentrated