反应详情

A solution of methyl 2-(3,4-dichlorophenyl)-2-methyl-4-oxochroman-3-carboxylate (490 mg, 1.34 mmol) in THF (2.0 mL) was diluted with methanol (4.0 mL) and treated at rt with sodium borohydride (51 mg, 1.34 mmol). Additional sodium borohydride was added after 4 h. After 2.5 h more the solution was concentrated under vacuum. The residue was partitioned between water (containing a few drops of 1.0 M aqueous sodium hydroxide) and ethyl acetate. The organic phase was dried over sodium sulfate and concentrated under vacuum to provide crude methyl 2-(3,4-dichlorophenyl)-4-hydroxy-2-methylchroman-3-carboxylate as a white solid (485 mg, 98%), which was used without further purification. Mass spectrum m/z 389, 391 (M+Na)+.

1. concentrationAfter 2.5 h more the solution was concentrated under vacuum
2. customThe residue was partitioned between water (containing a few drops of 1.0 M aqueous sodium hydroxide) and ethyl acetate
3. dry with materialThe organic phase was dried over sodium sulfate
4. concentrationconcentrated under vacuum