Water → (1R,2S)-(+)-cis-1-Amino-2-indanol

In 40 ml of acetonitrile, 3.0 g (20.1 mmol) of trans-(-)-1,2-indandiol (I': trans-configuration: 98.0%; cis-configuration: 2.0%; optical purity: 100% e.e.) was dissolved. At room temperature, 3.2 g (31.7 mol) of 97% sulfuric acid was dropwise added thereto in a period of 30 minutes. After the resulting mixture was stirred at room temperature for 1 hour, the compound (I') disappeared from an HPLC. To the reaction liquid, 20 ml of water was added. Immediately thereafter, the mixture was heated and 42 ml of an acetonitrile/water azeotrope was distilled off under normal pressure. Then, the mixture was subjected to a reflux for 1.5 hours to complete the reaction. The reaction liquid was cooled to room temperature and washed twice with 10 ml of dichloromethane. Then, its pH was adjusted to 10.5 by an addition of an aqueous solution of 25% sodium hydroxide. The grayish white scaly crystal deposited thereby was filtered off under reduced pressure, washed with a small quantity of water, and then dried under reduced pressure to yield 1.77 g of cis-(-)-1-aminoindan-2-ol (V) as a primary crystal. Then, the mother liquid after the deposition of the crystal was extracted with dichloromethane and the extracted phase was concentrated to yield 0.69 g of the compound (V) as a secondary crystal.