tert-butyl 2-cyclopropylideneacetate

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: At room temperature, 55 ml (55 mmol) of a 1 M solution of tetra-n-butylammonium fluoride in THF were added dropwise to a solution of 9.65 g (55.34 mmol) of [(1-ethoxycyclopropyl)oxy](trimethyl)silane, 25 g (66.41 mmol) of tert-butyl (triphenyl-λ5-phosphanylidene)-acetate and 8.11 g (66.41 mmol) of benzoic acid in 240 ml of THF. After 1 h of stirring, the reaction mixture was heated to 80° C. and stirred at this temperature for 2 h. Using a rotary evaporator, the solvent was then distilled off (200 mbar, bath temperature 40° C.). The residue obtained was taken up in diethyl ether and the mixture was cooled to 4° C. and allowed to stand at this temperature for 1 h. The resulting precipitate (triphenylphosphane oxide) was filtered off. Using a rotary evaporator, the filtrate was then freed from the solvent. The crude product obtained was purified chromatographically on silica gel (mobile phase cyclohexane/ethyl acetate 20:1). This gave 3.58 g (42% of theory) of the title compound. stirred at this temperature for 2 h a rotary evaporator the solvent was then distilled off (200 mbar, bath temperature 40° C.) The residue obtained the mixture was cooled to 4° C. to stand at this temperature for 1 h The resulting precipitate (triphenylphosphane oxide) was filtered off a rotary evaporator