反应详情

温度

-78 °C

Cuprous chloride (229 mg; 1.2 mmoles) was weighed into a 50 ml flask, and the inside atmosphere of the flask was purged with argon. Anhydrous ether (10 ml) was added, and then 0.60 ml (2.4 mmoles) of tri-n-butylphosphine was added at room temperature, followed by stirring for 10 minutes. The mixture was then cooled to -78° C., and a solution of 1.2 mmoles of dl 1-lithio-3-(t-butyldimethylsilyloxy)-trans-octene in a mixture of anhydrous ether and anhydrous hexane was added. The mixture was stirred at -78° C. for 30 minutes, and a solution of 212 mg (1.0 mmole) of dl 4-(t-butyldimethyl-silyloxy)-2-cyclopentenone in 5 ml of anhydrous ether was added dropwise. The mixture was stirred at -78° C. for 1 hour. Then, 0.15 ml of a boron trifluoride/ether complex was added, and the mixture was stirred at -78° C. for 10 minutes, and then at -40° C. for 20 minutes. Then, 5 ml of anhydrous tetrahydrofuran was added, and a solution of 221 mg (1.4 mmoles) of methyl 7-ketoheptanoate in 5 ml of anhydrous tetrahydrofuran was added. The mixture was stirred at -40° C. for 1.5 hours. The temperature of the mixture was gradually raised to room temperature, and the product was hydrolyzed with a saturated aqueous solution of ammonium chloride and extracted with ether. The organic layer was dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The crude product was subjected to silica gel column chromatography. From the eluates resulting from elution with hexane/ethyl acetate (=9/1), two stereoisomers, dl 2-(1-hydroxy-7-keto-8-oxanonyl)-3-[3-(t-butyldimethylsilyloxy)-1-trans-octenyl]-4-(t-butyldimethylsilyloxy)cyclopentanone, were obtained in an amount of 59 mg (TLC: Rf=0.39; developing solvent hexane/ethyl acetate=4/1) and 35 mg (TLC: Rf=0.35; developing solvent hexane/ethyl acetate=4/1), respectively.

1. customthe inside atmosphere of the flask was purged with argon
2. additionAnhydrous ether (10 ml) was added
3. additionwas added
4. stirringThe mixture was stirred at -78° C. for 30 minutes
5. stirringThe mixture was stirred at -78° C. for 1 hour
6. additionThen, 0.15 ml of a boron trifluoride/ether complex was added
7. stirringthe mixture was stirred at -78° C. for 10 minutes
8. waitat -40° C. for 20 minutes
9. stirringThe mixture was stirred at -40° C. for 1.5 hours
10. temperatureThe temperature of the mixture was gradually raised to room temperature
11. extractionextracted with ether
12. dry with materialThe organic layer was dried over anhydrous sodium sulfate
13. concentrationconcentrated under reduced pressure