Acetone → 2-Ethyl-1-hydroxy-4-phenylindan

To a 200-ml three-necked round flask (equipped with stirrer chip, Dimroth condenser, dropping funnel and thermometer) were introduced 0.85 g (22.6 mmol) of sodium boron hydride and 28 ml of ethanol. In a nitrogen atmosphere at room temperature, to the flask was dropwise added a solution obtained by dissolving 10.6 g (45.1 mmol) of the 2-ethyl-4-phenyl-l-indanone obtained above in 20 ml of ethanol. After the dropping was completed, the temperature of the system was elevated to 50° C. so as to further perform reaction for 3.5 hours. After the reaction, the system was cooled, and acetone was dropwise added to decompose the unreacted sodium boron hydride. Then, the reaction mixture was concentrated under reduced pressure and extracted with 50 ml of water and 50 ml of ether. The organic phase was separated, and the aqueous phase was extracted twice with 50 ml of ether, followed by mixing the organic phases together. The whole organic phase was washed with 100 ml of a saturated saline solution and dried with anhydrous Na2SO4. Then, the solvent was distilled off under reduced pressure to obtain 10.67 g of the aimed product (mixture of two kinds of isomers) as a viscous light yellow liquid (yield: 99%). The properties of the product thus obtained are described below.