反应详情

To a solution of dimethyl (2-oxopropyl)phosphonate (4.09 mL, 30 mmol) in tetrahydrofuran (200 mL) at 0° C. was added potassium tert-butoxide (3.22 g, 28.7 mmol). After 15 minutes, the reaction flask was moved to a 20° C. water bath and then a solution of methyl 2,2-dimethyl-3-oxopropanoate (3.39 g, 26 mmol) in tetrahydrofuran (10 mL) was added. After 20 hours, the opaque reaction mixture was partitioned between diethyl ether (100 mL) and water (100 mL). The layers were separated and the aqueous layer was extracted with diethyl ether (1×100 mL, 1×50 mL). The combined organic layers were washed with saturated aqueous sodium bicarbonate solution and brine, dried over sodium sulfate, filtered, and concentrated. The residue was purified by silica gel flash column chromatography (0-4% methanol/dichloromethane gradient) to afford methyl (3E)-2,2-dimethyl-5-oxohex-3-enoate (2.21 g, 12.21 mmol, 47% yield) as a light yellow oil. 1H NMR (500 MHz, CDCl3) δ 6.95 (d, J=16.3, 1H), 6.09 (d, J=16.3, 1H), 3.71 (s, 3H), 2.29 (s, 3H), 1.37 (d, J=2.3, 614).

1. customwas moved to a 20° C.
2. waitAfter 20 hours
3. customthe opaque reaction mixture
4. customwas partitioned between diethyl ether (100 mL) and water (100 mL)
5. customThe layers were separated
6. extractionthe aqueous layer was extracted with diethyl ether (1×100 mL, 1×50 mL)
7. washThe combined organic layers were washed with saturated aqueous sodium bicarbonate solution and brine
8. dry with materialdried over sodium sulfate
9. filtrationfiltered
10. concentrationconcentrated
11. customThe residue was purified by silica gel flash column chromatography (0-4% methanol/dichloromethane gradient)