反应详情

For the preparative resolution, racemic 1-phenylethyl acetate (50 mmol/l) in 10 mmol/l phosphate buffer pH 7.0 is incubated at 30° C. with the esterase according to the invention (1 unit esterase per 1 mmol ester) that was isolated according to example 1. The pH value is kept constant during the reaction by means of an automatic burette which titrates 0.1 mol/l NaOH. The reaction course is monitored by the consumption of sodium hydroxide. The enantiomeric excess of the product 1-phenylethanol as well as of the substrate 1-phenylethyl acetate is determined by HPLC on a chiral column (Chiracel OJ, Daicel Company). Once a 50% conversion is achieved, the enantiomeric excess of the retained substrate (R)-1-phenylethyl acetate is 96% and that of the product (S)-1-phenylethanol is 94% (enantioselectivity E>100). The reaction is terminated by extracting several fold with ethyl acetate. The organic phases are pooled and concentrated by evaporating the solvent. The (S)-1-phenylethanol obtained is separated from non-converted (R)-1-phenylethyl acetate by chromatography on silica gel.

1. customis incubated at 30° C. with the esterase
2. customwas isolated
3. customThe pH value is kept constant during the reaction by means of an automatic burette which
4. customThe reaction course is monitored by the consumption of sodium hydroxide
5. customThe reaction is terminated
6. extractionby extracting several fold with ethyl acetate
7. concentrationconcentrated
8. customby evaporating the solvent