Step 1: Preparation of Cyclopropylacetic Acid Methyl Ester
Cyclopropylacetic acid (1.08 g; 10.57 mmol) was dissolved in 50 ml of methanol. The solution was cooled to 0°C, and 5 ml of 96% sulfuric acid was added dropwise with stirring. The solution was kept at room temperature overnight, then poured into ice water, alkalized with 30% ammonium hydrate, and finally extracted with dichloromethane. The organic layer was dried over sodium sulfate and evaporated to dryness to give 1.1 g of oily product (90% yield), which could be used as is without further purification.
Step 2: Preparation of 2-CYCLOPROPYLETHANOL Sodium (85 mg; 0.004 mmol) was dissolved in 50 mL of methanol, and then 8.7 g (0.23 mol) of sodium borohydride was added. A solution of 3.7 g (0.032 mol) of methyl cyclopropyl acetate prepared according to Step 1 in 20 mL of methanol was added dropwise to the mixture with stirring. The reaction was refluxed for 6 hours, then 300 mL of brine was added, and the crude product was extracted with dichloromethane. The organic layer was dried over sodium sulfate and evaporated to dryness to give 1.52 g (55% yield) of the title compound.
