反应详情

An emulsion of (RS)-ethoxy-(2-fluoro-4-methoxy-phenyl)-acetic acid ethyl ester (1.11 g) in 0.1M NaCl, 3 mM Natriumphosphat buffer pH 7.0 (260 ml) was cooled to 4–5° C. and treated with lipase from Rhizomucor miehei. The reaction mixture was stirred for 4 days at 4–5° while maintaining the pH at 7 by gradual addition of 0.1N NaOH (totally 25.5 ml), then extracted with CH2Cl2 and then EtOAc. The organic layers were dried over Na2SO4, then concentrated to give (R)-ethoxy-(2-fluoro-4-methoxy-phenyl)-acetic acid ethyl ester (330 mg, 98.9% ee).

1. additiontreated with lipase from Rhizomucor miehei
2. temperaturewhile maintaining the pH at 7
3. extractionthen extracted with CH2Cl2
4. dry with materialThe organic layers were dried over Na2SO4
5. concentrationconcentrated