反应详情

To a stirred solution of (S)-1-(3-methylphenyl)-1,2-ethanediol (1.78 g, 11.7 mmol) in pyridine (35 ml) was added p-toluenesulfonyl chloride (2.46 g, 12.9 mmol), and 4-dimethylaminopyridine (1.58 g, 12.9 mmol) at 0° C. and the reaction mixture was stirred at 0° C. to rt for 17 h. The reaction mixture was acidified with 6N HCl aqueous solution and extracted with CH2Cl2. The extract was washed with water and brine, dried (Na2SO4), and concentrated to give 3.02 g of yellow oil, which was purified by column chromatography (silica gel: 100 g, ethyl acetate/hexane: 1/9 to 1/3) to afford 2.63 g (73%) of desired product as light yellow oil. Its optical purity was 97% ee by HPLC employing a chiral stationary phase (chiral pak AS, Daicel Chemical Industries, eluted with n-hexane/EtOH: 98/2; detection time: 55 min for (R)-isomer 59 min for (S)-isomer).

1. extractionextracted with CH2Cl2
2. washThe extract was washed with water and brine
3. dry with materialdried (Na2SO4)
4. concentrationconcentrated