反应详情

A 500 mL three-necked flask was flame dried and allowed to be cooled under nitrogen. (R,E)-triethyl ((4-(tributylstannyl)-1-(3-(trifluoromethyl)phenoxy)but-3-en-2-yl)oxy)silane (22.53 g, 35.46 mmol) and 200 mL tetrahydrofuran were added to the reaction flask, followed by dropwise addition of n-butyl lithium (22.2 mL, 1.6 M in hexane) at −70° C. A suspension solution of copper cyanide (3.18 g, 35.46 mmol) in 30 mL tetrahydrofuran was cooled to −10° C. and followed by dropwise addition of methyl lithium (17.76 mL, 2 M in ether). The homogenous organo-metallic solution was cooled and added into the reaction flask while stirring for 30 minutes. Then, a solution of (R,Z)-isopropyl 7-(3-triethylsilyloxy-5-oxocyclopent-1-en-1-yl)hept-5-enoate (4.5 g, containing 5% of 5,6-trans isomer) in 15 mL tetrahydrofuran at −70° C. was added to the reaction mixture for 10 minutes. After being stirred for another 20 minutes, the reaction mixture was poured into a mixture of 9/1 (v/v) saturated aqueous NH4Cl/NH4OH solution to be phase separated. The aqueous layer was extracted with ethyl acetate. The organic layers were combined and dried over anhydrous MgSO4. The solid was filtered off and organic solvent was evaporated off under vacuum. The crude product was purified by chromatography on silica gel using a mixture of hexane and ethyl acetate as a gradient eluent. Yield of the title compound was 5.10 g (59.3%).

1. temperatureA 500 mL three-necked flask was flame
2. customdried
3. temperatureto be cooled under nitrogen
4. additionadded into the reaction flask
5. stirringAfter being stirred for another 20 minutes
6. customseparated
7. extractionThe aqueous layer was extracted with ethyl acetate
8. dry with materialdried over anhydrous MgSO4
9. filtrationThe solid was filtered off
10. customorganic solvent was evaporated off under vacuum
11. customThe crude product was purified by chromatography on silica gel using
12. additiona mixture of hexane and ethyl acetate as a gradient eluent