反应详情

LHMDS (1 M solution in THF, 83 mL, 83 mmol) was added slowly to a cooled (−50° C.) solution of 1-(2,6-dimethylphenyl)-5-oxo-pyrrolidine-3-carboxylic acid methyl ester (17 g, 68.83 mmol) in THF (170 mL). After 5 min, 3-bromo-2-methylpropene (13.8 mL, 136.8 mmol) was added slowly at −50° C. and the resulting reaction mixture was warmed to room temperature and stirred for 2 h. Saturated aqueous NH4Cl solution (50 mL) was added, and the aqueous was extracted with EtOAc (3×100 mL). The combined organic layers were washed with water (100 mL), brine (100 mL), dried (Na2SO4) and evaporated. The residue was purified by automated flash chromatography (SiO2, 20→60% MTBE/hexanes) to give 1-(2,6-dimethylphenyl)-3-(2-methylallyl)-5-oxo-pyrrolidine-3-carboxylic acid methyl ester (10.9 g, 53% yield). LC-MS: R, (retention time): 2.44 min, MS: (ES) m/z 302.1 (M+H+).

1. customthe resulting reaction mixture
2. extractionthe aqueous was extracted with EtOAc (3×100 mL)
3. washThe combined organic layers were washed with water (100 mL), brine (100 mL)
4. dry with materialdried (Na2SO4)
5. customevaporated
6. customThe residue was purified by automated flash chromatography (SiO2, 20→60% MTBE/hexanes)