反应详情

The product of Example 1A ((3aR,6aR)-hexahydro-pyrrolo[3,4-b]pyrrole-1,5-dicarboxylic acid 5-benzyl ester 1-tert-butyl ester) (4.5 g, 12.5 mmole), was stirred with a mixture of dichloromethane and trifluoroacetic acid (15 ml/15 ml) for 2 hours. The solvent was removed under reduced pressure, and the residue was basified with saturated sodium bicarbonate, then extracted with dichloromethane (3×). The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by column chromatography (0.6% ammonium hydroxide and 6% methanol in dichloromethane) to provide the title compound. 1H NMR (CDCl3) δ ppm 7.28-7.40 (m, 5H) 5.12 (s, 2H) 3.74-3.87 (m, 1H) 3.53-3.71 (m, 2H) 3.36-3.48 (m, 1H) 3.18-3.32 (m, 1H) 3.01-3.13 (m, 1H) 2.88-3.01 (m, 1H) 2.70-2.83 (m, 1H) 1.87-2.03 (m, 1H) 1.58-1.76 (m, 1H). MS: (M+H)+=247.

1. customThe solvent was removed under reduced pressure
2. extractionextracted with dichloromethane (3×)
3. washThe combined organic layers were washed with brine
4. dry with materialdried over sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated under reduced pressure
7. customThe residue was purified by column chromatography (0.6% ammonium hydroxide and 6% methanol in dichloromethane)