tert-butyl 2-cyclobutylideneacetate

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

Procedure: Under argon and at room temperature, 3.0 g (42.8 mmol) of cyclobutanone were dissolved in 160 ml of dichloromethane, and 20.95 g (55.64 mmol) of tert-butyl (triphenyl-λ5-phosphanylidene) acetate and 0.68 g (5.56 mmol) of benzoic acid were then added. The reaction mixture was stirred at room temperature overnight and then concentrated to dryness. The residue was triturated with 25 ml of diethyl ether, and the mixture was stored at 4° C. for 12 h. The precipitated triphenylphosphane oxide was filtered off and the filtrate was concentrated to dryness. The crude product obtained was purified chromatographically on silica gel (mobile phase cyclohexane/ethyl acetate 20:1). This gave 9.3 g (99% of theory) of the title compound. concentrated to dryness The residue was triturated with 25 ml of diethyl ether the mixture was stored at 4° C. for 12 h The precipitated triphenylphosphane oxide was filtered off the filtrate was concentrated to dryness