反应详情

To a solution of 16 g of (2R)-2-(4-chlorophenyl)-2-hydroxyacetic acid (cf. JP-Hei 6 (1994)-165695A) in 440 ml of hexane/toluene (10:1), 23 ml of pivalaldehyde and 326 mg of p-toluenesulfonic acid monohydrate were added by the order stated, followed by 12 hours' heating under reflux while removing the generated water with Dean-Stark trap. The reaction liquid was diluted with ethyl acetate, washed with saturated aqueous sodium hydrogencarbonate solution and saturated brine, and dried over anhydrous sodium sulfate. Distilling the solvent off under reduced pressure, 14 g of the title compound was obtained.

1. temperature' heating
2. temperatureunder reflux
3. customwhile removing the generated water with Dean-Stark trap
4. customThe reaction liquid
5. washwashed with saturated aqueous sodium hydrogencarbonate solution and saturated brine
6. dry with materialdried over anhydrous sodium sulfate
7. distillationDistilling the solvent off under reduced pressure