反应详情

温度

-60 °C

To a solution of intermediate 47 (75.93 mmol) in dry tetrahydrofuran (300 mL) at −78° C. under nitrogen was added n-butyllithium 2.5M solution in hexane (275 mmol). After completion of addition, the mixture was stirred under nitrogen between −70° C. and −80° C. for 30 min, and then allowed to warm up to −60° C. The reaction was carefully quenched with methanol (20 mL), maintaining the temperature below −40° C. The reaction mixture was then allowed to reach to 0° C., and water (100 mL) and ethyl acetate (100 mL) were added. The layers were separated and the organic was washed sequentially with a diluted HCl solution and brine. After evaporation in vacuo of the organic layer, the residue was purified by silica gel chromatography (eluent: DCM to DCM/methanol (1%)) to give compound 48 as a white foam in 52% yield. 1H NMR (DMSO-d6, 400 MHz) δ (ppm) 1.16-1.37 (2s, 9H), 1.78-1.94 (m, 3H), 2.08-2.21 (m, 1H), 3.26-3.34 (m, 1H), 3.42-3.50 (m, 1H), 4.63-4.74 (m, 1H), 7.07-7.10 (m, 1H), 12.09-12.13 (m, 1H); MS (ESI, EI+) m/z=316.23-318.24 (MH+).

1. additionAfter completion of addition
2. customThe reaction was carefully quenched with methanol (20 mL)
3. temperaturemaintaining the temperature below −40° C
4. customto reach to 0° C.
5. additionwater (100 mL) and ethyl acetate (100 mL) were added
6. customThe layers were separated
7. washthe organic was washed sequentially with a diluted HCl solution and brine
8. customAfter evaporation in vacuo of the organic layer
9. customthe residue was purified by silica gel chromatography (eluent: DCM to DCM/methanol (1%))