反应详情

A dried, 25 mL round-bottom flask equipped magnetic stirring bar is cooled to room temperature under a stream of nitrogen. To this is added (−)-DIP-Chloride (6.76 mmol, 2.17 g, 1.2 eq) and THF (10 mL), and the mixture is cooled to −25° C., followed by the addition of methyl 4-(3-methoxyphenyl)-4-oxobutanoate (5.63 mmol). The resulting mixture is then stirred at −20° C. to −30° C. for 10 h. Then, diethanolamine (12.39 mmol, 2.2 eq) is added at −20° C., and the mixture is warmed to room temperature and stirred overnight. This mixture is then filtered, evaporated, and the residue is purified on silica gel (0-33% ethyl acetate in hexane) to give (S)-methyl 4-hydroxy-4-(3-methoxyphenyl)butanoate (985 mg, 79%; >95% based on recovered starting material) as a clear colorless oil. 1H NMR (CDCl3) δ 7.33-7.27 (m, 1H), 6.92-6.84 (m, 3H), 5.52-5.46 (m, 1H), 3.82 (s, 1H), 3.48 (s, 1H), 2.71-2.61 (m, 3H), 2.26-2.12 (m, 1H).

1. customA dried, 25 mL round-bottom flask equipped magnetic stirring bar
2. temperaturethe mixture is cooled to −25° C.
3. temperaturethe mixture is warmed to room temperature
4. stirringstirred overnight
5. filtrationThis mixture is then filtered
6. customevaporated
7. customthe residue is purified on silica gel (0-33% ethyl acetate in hexane)