ethyl 7-oxospiro[3.5]nonane-8-carboxylate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: 20.6 mmol of 3-[1-(ethoxycarbonylethyl)cyclobutyl]propionic acid ethyl ester in solution in tetrahydrofuran are added at 0° C. to 22.7 mmol of 95% sodium hydride in suspension in 15 ml of tetrahydrofuran. The reaction mixture is refluxed for 4 hours and then 49 ml of acetic acid are added. The tetrahydrofuran is evaporated off and the residue obtained is extracted with ethyl acetate. The combined organic phases are washed, filtered, dried and evaporated to yield an oil, which is subjected to chromatography on silica (eluant: dichloromethane/ethyl acetate 95/5) to yield the expected product. The reaction mixture is refluxed for 4 hours The tetrahydrofuran is evaporated off the residue obtained is extracted with ethyl acetate The combined organic phases are washed filtered dried evaporated to yield an oil, which