反应详情

The ether solution was transferred to a 100 mL round-bottom flask equipped with a magnetic stir bar, and DIPEA (1.1 eq., 0.96 mL, 5.5 mmol) was added via syringe. Ethyl 2-chloro-2-(hydroxyimino)acetate (1 eq., 758 mg, 5.00 mmol) was dissolved in DCM (50 mL) and placed in a dropping funnel. The DCM solution was added dropwise to the vigorously stirred ether reaction mixture over a period of 2 h. The resulting solution was stirred at RT for 3 days. The solvent was removed under reduced pressure, and the residue was purified by column chromatography using a 24-g SiO2 pre-packed column eluting with EtOAc/hexanes, 0:1 to 2:3, v/v over 30 min, yielding 264 mg (25%) of the desired ester. 1H-NMR (400 MHz, CDCl3) δ: 4.35 (q, J=7.2 Hz, 2H), 3.89 (ddd, J=11.7, 8.6, 3.4 Hz, 2H), 3.63-3.76 (m, 2H), 2.99 (s, 2H), 1.87-1.98 (m, 2H), 1.74-1.87 (m, 2H), 1.37 (t, J=7.2 Hz, 3H).

1. customequipped with a magnetic stir bar
2. customplaced in a dropping funnel
3. customThe solvent was removed under reduced pressure
4. customthe residue was purified by column chromatography
5. washeluting with EtOAc/hexanes, 0:1 to 2:3, v/v over 30 min