反应详情

温度

-20 °C

To 85B (2.46 g, 6.95 mmol) in DMF (20 mL) at −20° C. was added lithium bis(trimethylsilyl)amide (1.0 M in THF, 12.2 mL, 12.2 mmol) dropwise. The mixture was stirred at −20° C. for 20 min followed by addition of allyl bromide (3.0 mL, 34.8 mmol). After 1.0 h stirring at −20° C., the reaction was quenched with sat. NH4Cl and warmed to rt. It was extracted with EtOAc (3×50 mL), the organic layer was washed with brine and dried over Na2SO4. After removal of solvent, the crude was purified by silica gel column chromatography using gradient EtOAc in hexanes to give 85C (2.2 g, 80% yield). HPLC and 1H NMR indicated 85C is a mixture of two diastereoisomers in a ratio of 5:1. Major isomer: 1H NMR (400 MHz, CDCl3) δ ppm 0.67-0.76 (m, 2H) 1.15-1.20 (m, 2H) 1.25 (s, 9H) 2.12-2.20 (m, 1H) 3.02 (dd, J=17.14, 6.59 Hz, 1H) 4.05 (dd, J=17.14, 4.83 Hz, 1H) 5.06-5.26 (m, 5H) 6.00 (ddd, J=17.03, 10.22, 7.03 Hz, 1H) 7.70 (t, J=8.13 Hz, 1H) 8.10 (dd, J=8.79, 2.64 Hz, 1H) 8.49 (d, J=2.64 Hz, 1H), LC-MS 395 (M+H).

1. stirringAfter 1.0 h stirring at −20° C.
2. customthe reaction was quenched with sat. NH4Cl
3. temperaturewarmed to rt
4. extractionIt was extracted with EtOAc (3×50 mL)
5. washthe organic layer was washed with brine
6. dry with materialdried over Na2SO4
7. customAfter removal of solvent
8. customthe crude was purified by silica gel column chromatography