32249-35-7

67-56-1

2033-24-1

4023-34-1

32249-35-7

Cyclo(sub)isopropyl malonate (50 g; 347 mmol) was dissolved in chloroform (550 ml) followed by addition of pyridine (56 g; 700 mmol). A solution of cyclopropanecarbonyl chloride (40 g; 383 mmol) in chloroform (50 ml) was added slowly and dropwise under cooling in an ice bath, keeping the reaction temperature below 10 °C. After the dropwise addition, the reaction mixture was continued to be stirred in an ice bath for 1 h. Subsequently, the ice bath was withdrawn and the reaction was stirred for another 1 h at room temperature. After completion of the reaction, the reaction was again cooled in an ice bath and the reaction was quenched by slow addition of 1N aqueous hydrochloric acid solution (500 ml). The reaction product was extracted with chloroform, the organic phase was washed sequentially with water, dried over anhydrous sodium sulfate and concentrated under reduced pressure to remove the solvent. Methanol (500 ml) was added to the concentrated residue and heated to reflux for 3 hours. After the reaction solution was cooled to room temperature, methanol was removed by distillation under reduced pressure, and the residue was purified by distillation under reduced pressure to obtain 3-cyclopropyl-3-oxopropanoic acid methyl ester 40g, yield 80%. Physical properties: boiling point 80°C (10mmHg).