反应详情

To a suspension of sodium hydride (0.27 g, 6.63 mmol, 60% oil dispersion) in dry tetrahydrofuran (10 ml), was added dropwise with vigorous stirring a solution of 3-methoxycarbonylcyclobutanone (0.707 g, 5.52 mmol) and methyl isocyanoacetate (0.6 g, 6.07 mmol) in dry tetrahydrofuran (20 ml) over 5 minutes. The reaction mixture was stirred at room temperature for 2 hours, cooled to 0° C. and 10% aqueous acetic acid (20 ml) added dropwise. The organic solvent was removed in vacuo and the resulting solution extracted with dichloromethane (3×20 ml). The combined extracts were washed with water, dried over anhydrous magnesium sulphate and evaporated to give an oil. The crude product was purified by flash chromatography, eluting with ethyl acetate-hexane (1:1, 3:2), to give methyl N-formyl-α-(3-methoxycarbonylcyclobutylidene)glycinate as a colourless oil.

1. additionwas added dropwise
2. temperaturecooled to 0° C.
3. customThe organic solvent was removed in vacuo
4. extractionthe resulting solution extracted with dichloromethane (3×20 ml)
5. washThe combined extracts were washed with water
6. dry with materialdried over anhydrous magnesium sulphate
7. customevaporated
8. customto give an oil
9. customThe crude product was purified by flash chromatography
10. washeluting with ethyl acetate-hexane (1:1, 3:2)