反应详情

To a stirred solution of sodium borohydride (0.4 g) in 0.02 N aqueous sodium hydroxide (30 ml) was added dropwise a solution of 4-oxo-10-(2-oxopropyl)-6,7,8,9-tetrahydro-4H-naphtho[2,3-b]pyran-2carboxylic acid (2.3 g) in 0.02N aqueous sodium hydroxide (100 ml). The resulting solution was stirred at ambient temperature for 20 hours, then cooled in ice and acidified with dilute hydrochloric acid. The precipitate was filtered washed with water and dried giving the title compound as a white solid, mp 235°.

1. temperaturecooled in ice
2. filtrationThe precipitate was filtered
3. washwashed with water
4. customdried