反应详情

温度

-78 °C

n-BuLi (1.6M in hexane, 6.4 mL, 10.3 mmol) was added slowly to 2,2,6,6-tetramethylpiperidine at -10° C. and the slurry was stirred 30 min, then cooled to -78° C. and diluted with 25 mL degassed THF. This solution was transferred via cannula into a 50 mL (degassed) THF solution of ester from Step 1 (4.15 g, 9.3 mmol) at -78° C. After stirring 1-- h, HMPA (1.6 mL, 9.3 mmol) was added and 30 min later CH3I (5.8 mL, 93 mmol) was added. The reaction mixture was stirred 12 h at -78° C., then quenched with saturated NH4Cl and extracted with Et2O and ethyl acetate. The organic phase was washed with aqueous Na2S2O5, water, brine and dried over MgSO4. Purification by flash chromatography (15% ethyl acetate in hexane) provided 2.5 g of the title compound.

1. additiondiluted with 25 mL
2. customdegassed THF
3. additionwas added
4. stirringThe reaction mixture was stirred 12 h at -78° C.
5. customquenched with saturated NH4Cl
6. extractionextracted with Et2O and ethyl acetate
7. washThe organic phase was washed with aqueous Na2S2O5, water, brine
8. dry with materialdried over MgSO4
9. customPurification by flash chromatography (15% ethyl acetate in hexane)