反应详情

To a solution of Intermediate 74f (0.44 g, 0.85 mmol) in EtOAc (5 mL) was added 1N aqueous NaOH solution (1.7 mL, 1.7 mmol) followed by 2,2,2-trichloroethylchloroformate (0.13 mL, 0.93 mmol). The reaction was stirred at RT for 4 h then treated with another portion of 2,2,2-trichloroethylchloroformate (35 μL, 0.25 mmol) and stirred over the weekend. The reaction was treated with another portion of 2,2,2-trichloroethylchloroformate (35 μL, 0.25 mmol) and stirred for 1 h then diluted with EtOAc and water and the layers were separated. The aqueous layer was then extracted with EtOAc (2×). The combined organic layers were washed with saturated aqueous sodium bicarbonate solution, and brine, dried (Na2SO4), filtered and evaporated in vacuo. The residue was purified by FCC, using 0-4% MeOH in DCM, to give the title compound (0.47 g, 80%). 1H NMR (300 MHz, CDCl3): 0.96 (18H, d, J=6.8 Hz), 1.01-1.17 (3H, m), 1.25 (9H, s), 1.38-1.51 (4H, m), 1.54-1.75 (2H, m), 3.36-3.45 (1H, m), 3.58-3.68 (1H, m), 3.68-3.77 (1H, m), 3.97-4.07 (1H, m), 4.24 (2H, t, J=4.7 Hz), 4.51 (1H, t, J=3.2 Hz), 4.59 (2H, s), 4.69-4.73 (2H, m), 6.26 (1H, s), 7.63 (1H, s), 7.74 (1H, s).

1. stirringstirred over the weekend
2. stirringstirred for 1 h
3. customthe layers were separated
4. extractionThe aqueous layer was then extracted with EtOAc (2×)
5. washThe combined organic layers were washed with saturated aqueous sodium bicarbonate solution, and brine
6. dry with materialdried (Na2SO4)
7. filtrationfiltered
8. customevaporated in vacuo
9. customThe residue was purified by FCC