反应详情

To a suspension of methyltriphenylphosphonium bromide (0.78 g, 2.18 mmol) in 5 mL of benzene under argon at room temperature was added a 0.5M solution of potassium hexamethyldisilazide in toluene (4.4 mL, 2.2 mmol), and the yellow solution was stirred for 5 min. A solution of keto-ester 3 (0.51 g, 1.455 mmol) in 7 mL of benzene was added, and the orange solution was stirred for 1 h at room temperature. The reaction mixture was poured into saturated aqueous NaHCO3 and extracted with 40% ethyl acetate/hexane. The combined organic layers were dried over anhydrous MgSO4, filtered through a plug of silica gel, and concentrated to afford a solid. Flash chromatography (30% dichloromethane/hexane) yielded the desired product 16 as a white solid (0.405 g, 80%): m.p. 117°-118° C.; Rf 0.2 (25% CH2Cl2 /hexane). The structure of the product was also confirmed using IR, 1H NMR and mass spectroscopy.

1. stirringthe orange solution was stirred for 1 h at room temperature
2. extractionextracted with 40% ethyl acetate/hexane
3. dry with materialThe combined organic layers were dried over anhydrous MgSO4
4. filtrationfiltered through a plug of silica gel
5. concentrationconcentrated
6. customto afford a solid