Hydrochloric Acid → tert-Butyl 3-[(1E)-3-ethoxy-3-oxoprop-1-en-1-yl]azetidine-1-carboxylate

Participants

Reaction Steps

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)-2-ethoxycarbonylvinyl)azetidine-1-carboxylic acid tert-butyl ester.

Provenance & Evidence