反应详情

温度

-78 °C

n-Butyl lithium 1.6M solution in hexanes (0.88 ml, 1.4 mmol) was added dropwise to a solution of commercially available 1-bromo-4-[(phenylmethyl)oxy]benzene (390 mg, 1.48 mmol) in dry THF (2 ml) at −78° C. under nitrogen atmosphere. The resulting suspension was stirred at −78° C. for 40 minutes and then it was added dropwise to a solution of 1-(1,1-dimethylethyl) 2-methyl (2S)-5-oxo-1,2-pyrrolidinedicarboxylate (D1, 300 mg, 1.23 mmol) in dry THF (2.4 ml) previously cooled to −78° C. The mixture was stirred at −78° C. for 40 minutes and at 40° C. for 1 h, then it was quenched at −40° C. with an aqueous saturated ammonium chloride solution. The mixture was diluted with water and extracted with ethyl acetate. The organic phase was then washed with brine, dried over Na2SO4, and evaporated under reduced pressure to give the crude material, which was purified by chromatography on silica gel eluting with cyclohexane/ethylacetate (95:5), thus affording the title compound as a white solid (170 mg, 32%); Rf (cyclohexane:ethyl acetate=8:2): 0.30; 1HNMR (300 MHz, CDCl3) δ(ppm): 7.95 (d, 2H), 7.50-7.33 (m, 5H), 7.03 (d, 2H), 5.20 (bs, 1H), 5.15 (s, 2H), 4.45-4.35 (m, 1H), 3.78 (s, 3H), 3.15-2.95 (m, 2H), 2.36-2.26 (m, 1H), 2.16-2.02 (m, 1H), 1.45 (s, 9H).

1. temperaturepreviously cooled to −78° C
2. stirringThe mixture was stirred at −78° C. for 40 minutes and at 40° C. for 1 h
3. customit was quenched at −40° C. with an aqueous saturated ammonium chloride solution
4. additionThe mixture was diluted with water
5. extractionextracted with ethyl acetate
6. washThe organic phase was then washed with brine
7. dry with materialdried over Na2SO4
8. customevaporated under reduced pressure
9. customto give the crude material, which
10. customwas purified by chromatography on silica gel eluting with cyclohexane/ethylacetate (95:5)