931-97-5

1123-28-0

1. A solution of sodium metabisulfite (4.84 g, 0.025 mol) in distilled water (20 mL) was added slowly and dropwise to a stirred mixture of cyclohexanone (4.02 g, 0.041 mol) and potassium cyanide (3.3 g, 0.051 mol) in water (20 mL) over a period of 30 minutes. The reaction mixture was stirred continuously at 25°C for 8 hours. Upon completion of the reaction, the mixture was extracted with ethyl acetate (2 x 100 mL), the organic phases were combined and dried with anhydrous magnesium sulfate, and concentrated under reduced pressure to give 3.8 g of 1-hydroxycyclohexanecarbonitrile as an oil. 2. 1-hydroxycyclohexanecarbonitrile obtained above was dissolved in acetic acid (12.5 mL) and diluted slowly by adding concentrated hydrochloric acid (37.5 mL). The reaction solution was heated to reflux for 6 hours and subsequently concentrated under reduced pressure to an oily residue. The residue was partitioned between water (50 mL) and ethyl acetate (50 mL), the organic phase was separated, dried over anhydrous magnesium sulfate and concentrated under reduced pressure to give a solid. The solid was washed with hexane (25 mL) and filtered to give 2.84 g of 1-hydroxycyclohexanecarboxylic acid. 3. 1-Hydroxycyclohexanecarboxylic acid was dissolved in methanol (50 mL) and catalyzed by adding a drop of concentrated sulfuric acid. The reaction solution was heated to reflux for 16 hours and subsequently concentrated under reduced pressure to an oily residue. The residue was dissolved in ethyl acetate (50 mL) and washed with 5% sodium bicarbonate solution (50 mL). The organic phase was dried with anhydrous magnesium sulfate, filtered, concentrated under reduced pressure, and finally purified by silica gel column chromatography (eluent: 80% hexane/20% ethyl acetate) to afford 2.71 g of 1-hydroxycyclohexanecarboxylic acid methyl ester as a clear colorless oil.