反应详情

To a solution of ethyl 3-oxocyclobutanecarboxylate (3.0 g, 21.1 mmol) in anhydrous Et2O (60 mL), cooled to −80° C., was added dropwise a solution of (4-methoxyphenyl)magnesium bromide (50.6 mL, 25.3 mmol, 2M in THF). The reaction mixture was allowed to warm to RT and stir for 2 h. The reaction mixture was quenched with a saturated aq. solution of NH4Cl (20 mL) and then extracted with EtOAc (3×30 mL) The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated. The crude product was purified by silica gel chromatography (40 g REDISEP® column, eluting with 15% EtOAc in hexanes). Fractions containing the product were combined and evaporated to afford Intermediate 279A as a colorless liquid (3 g, 57%). 1H NMR (300 MHz, DMSO-d6) δ ppm 7.42 (d, J=8.7 Hz, 2H), 6.89 (d, J=8.7 Hz, 2H), 5.58 (s, 1H), 4.08 (d, J=7.2 Hz, 2H), 3.75 (s, 3H), 2.76-2.67 (m, 1H), 2.60 (s, 2H), 2.47 (s, 2H), 1.22-1.16 (m, 3H).

1. customThe reaction mixture was quenched with a saturated aq. solution of NH4Cl (20 mL)
2. extractionextracted with EtOAc (3×30 mL) The combined organic layers
3. washwere washed with brine
4. dry with materialdried over Na2SO4
5. filtrationfiltered
6. concentrationconcentrated
7. customThe crude product was purified by silica gel chromatography (40 g REDISEP® column, eluting with 15% EtOAc in hexanes)
8. additionFractions containing the product
9. customevaporated