反应详情

To a stirred solution of (1S,3′R,4′S,5′S,6′R)-6′-(aminomethyl)-5-chloro-6-(4-ethylbenzyl)-3′,4′,5′,6′-tetrahydro-3H-spiro[isobenzofuran-1,2′-pyran]-3′,4′,5′-triol (20 mg, 0.047 mmol) and 0.04 mL of pyridine in 1 mL of dichloromethane, was added acetic anhydride (45 μL, 0.048 mmol) and 3 mg of 4-dimethylaminopyridine. After being stirred for 2 h at ambient temperature, the reaction mixture was diluted with 20 mL of dichloromethane, washed with 1 M hydrochloric acid and concentrated. The residue was dissolved in 1 mL of methanol and cooled in an ice bath. After addition of 0.3 mL of 4 M potassium hydroxide solution, the mixture was stirred for 2 h at ambient temperature. The reaction mixture was then neutralized with 1 M hydrochloric acid and concentrated. The residue was partitioned between aqueous sodium hydrogen carbonate solution and ethyl acetate, and the organic layer was separated and dried over sodium sulfate. Concentration under reduced pressure provided the crude product, which was purified by preparative TLC to give 5 mg of title compound. 1H NMR (CD3OD, 400 MHz) δ 7.25 (s, 1H), 7.11 (s, 1H), 6.99 (s, 4H), 5.00 (d, J=12.6 Hz, 1H), 4.95 (d, J=12.6 Hz, 1H), 4.00 (d, J=15.4 Hz, 1H), 3.95 (d, J=15.4 Hz, 1H), 3.71-3.57 (m, 3H), 3.45 (dd, J=14.4, 2.8 Hz, 1H), 3.17-3.11 (m, 2H), 2.48 (q, J=7.6 Hz, 2H), 1.09 (t, J=7.6 Hz, 3H); MS ESI (m/z) 484 (M+Na)+, calc. 461.

1. washwashed with 1 M hydrochloric acid
2. concentrationconcentrated
3. dissolutionThe residue was dissolved in 1 mL of methanol
4. temperaturecooled in an ice bath
5. additionAfter addition of 0.3 mL of 4 M potassium hydroxide solution
6. stirringthe mixture was stirred for 2 h at ambient temperature
7. concentrationconcentrated
8. customThe residue was partitioned between aqueous sodium hydrogen carbonate solution and ethyl acetate
9. customthe organic layer was separated
10. dry with materialdried over sodium sulfate
11. concentrationConcentration under reduced pressure
12. customprovided the crude product, which
13. customwas purified by preparative TLC