反应详情

Triethyl phosphonoacetate (1.9 mL; 9.72 mmol) was dissolved in tetrahydrofuran (30 mL). Potassium tert-butoxide (1.1 g; 9.72 mmol) was added portionwise. 3-Formylazetidine-1-car-boxylic acid tert-butyl ester (1.0 g; 5.40 mmol) was dissolved in tetrahydrofuran (6 mL) and added to the reaction mixture. The reaction mixture was stirred for 1 hour at room temperature. Ethyl acetate (100 mL) and hydrochloric acid (100 mL; 1 N) were added and the phases were separated. The aqueous phase was extracted with ethyl acetate (2×50 mL) and the combined organic phases were washed with saturated sodium hydrogen carbonate (100 mL), dried (magnesium sulfate) and evaporated in vacuo. The residue was chromatographed on silica (3×30 cm) using ethyl acetate/heptane (1:1) as eluent to afford 1.0 g of 3-((E)-2ethoxycarbonylvinyl)azetidine-1-carboxylic acid tert-butyl ester.

1. additionadded to the reaction mixture
2. customthe phases were separated
3. extractionThe aqueous phase was extracted with ethyl acetate (2×50 mL)
4. washthe combined organic phases were washed with saturated sodium hydrogen carbonate (100 mL)
5. dry with materialdried (magnesium sulfate)
6. customevaporated in vacuo
7. customThe residue was chromatographed on silica (3×30 cm)