反应详情

温度

-78 °C

To a solution of intermediate 5B (˜0.05 M in THF) at −78° C. was added dropwise MeMgBr (3.0M in Et2O, 3 eq). The reaction was stirred at −78° C. for 1.5-2 h (quench small aliquot in 10% MeOH/DCM, spot TLC-silica gel, 30% EtOAc/Hex-stain with 5% HCl/MeOH, heat and then ninhydrin, heat). Quench reaction by addition of HOAc (3 eq) at −78° C. Warm to RT, dilute with EtOAc and wash with a 1:1 mixture of sat. aq. NaHCO3 and sat aq. NaCl. Back extract aqueous layer. Combine organic extracts, dry over MgSO4, filter and concentrate. Purification by flash chromatography (silica gel, step gradient 0-10-20% EtOAc in hexane) provided the title compound.

1. customquench small aliquot in 10% MeOH/DCM
2. temperaturespot TLC-silica gel, 30% EtOAc/Hex-stain with 5% HCl/MeOH, heat
3. temperatureninhydrin, heat)
4. customQuench
5. customreaction
6. temperatureWarm to RT
7. washwash with a 1:1 mixture of sat. aq. NaHCO3
8. extractionBack extract aqueous layer
9. dry with materialCombine organic extracts, dry over MgSO4
10. filtrationfilter
11. concentrationconcentrate
12. customPurification by flash chromatography (silica gel, step gradient 0-10-20% EtOAc in hexane)