反应详情

温度

0 °C

n-butyl lithium (1.17 mmol, 0.47 ml, 2.5 M) was added dropwise to a solution of diisopropylamine (130 mg, 1.29 mmol, 0.18 ml) in THF (8 ml) at −78° C. The solution was warmed to 0° C., stirred for 15 mins, and cooled back to −78° C. Ethyl propiolate (126 mg, 1.29 mmol, 0.13 ml) was added dropwise and the solution stirred for 1 hr at −78° C. A solution of tert-butyl 3-oxoazetidine-1-carboxylate (200 mg, 1.17 mmol) in THF (2 ml) was added dropwise, stirring continued for 30 mins, and the solution warmed to 0° C. and stirred for a further 15 mins. The reaction was quenched with Sat NH4Cl (20 ml) and extracted into ethyl acetate (20 ml), dried (Na2SO4), and concentrated to give a brown oil. The oil was purified by flash column chromatography eluting with 30% ethylacetate/hexanes to give the title compound as a colorless oil 0.20 g, 64%. 1H NMR (CDCl3, 400 MHz) 1.33 (3H, t), 1.48 (9H, s), 2.92 (1H, s), 4.04 (2H, d), 4.22-4.31 (4H, m).

1. temperaturecooled back to −78° C
2. stirringthe solution stirred for 1 hr at −78° C
3. stirringstirring
4. waitcontinued for 30 mins
5. temperaturethe solution warmed to 0° C.
6. stirringstirred for a further 15 mins
7. customThe reaction was quenched with Sat NH4Cl (20 ml)
8. extractionextracted into ethyl acetate (20 ml)
9. dry with materialdried (Na2SO4)
10. concentrationconcentrated
11. customto give a brown oil
12. customThe oil was purified by flash column chromatography
13. washeluting with 30% ethylacetate/hexanes