反应详情

温度

35 °C

Methyltriphenylphosphonium bromide (22 g, 61.6 mmol) was added to a solution of potassium tert-butoxide (6.5 g, 57.6 mmol) in anhydrous diethyl ether (450 ml) at 0° C. under nitrogen and the resulting bright yellow mixture stirred for 30 minutes. A solution of 1-tert-butyl 2-methyl (2S)-4-oxo-1,2-pyrrolidinedicarboxylate (10 g, 41.1 mmol in 150 ml anhydrous diethyl ether) was added slowly to the reaction mixture, which was then warmed at 35° C. for 3 h. Saturated aqueous ammonium chloride solution (0.5 ml) was then added. The organic layer was removed, and the aqueous washed with diethyl ether (3×5 ml). The combined organic layers were dried with brine and magnesium sulfate before filtering and removal of solvent. Silica gel chromatography, eluting with 15% ethyl acetate in hexanes gave the desired product 6.9 g (70% yield) as a off-white wax.

1. customThe organic layer was removed
2. washthe aqueous washed with diethyl ether (3×5 ml)
3. dry with materialThe combined organic layers were dried with brine and magnesium sulfate
4. filtrationbefore filtering
5. customremoval of solvent
6. washSilica gel chromatography, eluting with 15% ethyl acetate in hexanes