反应详情

To a solution of diisopropylamine (0.5 mL, 3.52 mmol) in 7 mL of THF at -78° C. under argon was added a 1.6M solution of n-butyllithium in hexane (2.2 mL, 3.52 mmol). The mixture was stirred for 25 min, and a solution of ketone 39 (0.78 g, 3.2 mmol) in 4 mL of THF was added slowly. The mixture was stirred for 20 min, and a solution of ethyl (E)-3-formyl-2-butenoate 40 (0.45 g, 3.2 mmol) (ethyl (E)-3-formyl-2-butenoate 40 is readily available from Fluka) in 3 mL of THF was added slowly. The mixture was stirred for 35 min at -78° C., poured into saturated aqueous NH4Cl, and extracted with 40% ethyl acetate/hexane. The combined organic layers were dried over anhydrous MgSO4, filtered, and concentrated to afford a light-yellow solid. Flash chromatography yielded the desired alcohol 41 as a white crystalline solid (0.98 g, 80%): m.p. 126°-128° C.; Rf 0.13 (10% ethyl acetate/hexane). The structure of the product was also confirmed using IR, 1H NMR and mass spectroscopy.

1. stirringThe mixture was stirred for 20 min
2. additionwas added slowly
3. stirringThe mixture was stirred for 35 min at -78° C.
4. extractionextracted with 40% ethyl acetate/hexane
5. dry with materialThe combined organic layers were dried over anhydrous MgSO4
6. filtrationfiltered
7. concentrationconcentrated
8. customto afford a light-yellow solid