反应详情

温度

-78 °C

To a cold (−78° C.), stirred suspension of triphenylmethyl phosphonium bromide (10.5 g, 29.4 mmol) in THF (80 mL) was added n-BuLi (11.4 mL of a 2.5M solution in hexanes, 28.4 mmol) dropwise. Upon stirring the resulting orange suspension for 45 min at −78° C., a solution of the product of step B (3.8 g, 14.7 mmol) in THF (25 mL) was added dropwise. The cold bath was removed and the mixture was stirred at RT for 2 h before being quenched with a saturated aqueous solution of NH4Cl. The organic layer was separated and the aqueous layer was extracted with Et2O (3×). The combined organic layers were washed with brine (1×), dried over anhydrous MgSO4, filtered, and concentrated under vacuum to leave a residue which was purified by column chromatography on silica (elution with 5:1 hexane:ethyl acetate) to yield the desired alkene. MS (ESI) m/z 258 [M+H]+.

1. stirringUpon stirring the resulting orange suspension for 45 min at −78° C.
2. customThe cold bath was removed
3. stirringthe mixture was stirred at RT for 2 h
4. custombefore being quenched with a saturated aqueous solution of NH4Cl
5. customThe organic layer was separated
6. extractionthe aqueous layer was extracted with Et2O (3×)
7. washThe combined organic layers were washed with brine (1×)
8. dry with materialdried over anhydrous MgSO4
9. filtrationfiltered
10. concentrationconcentrated under vacuum
11. customto leave a residue which
12. customwas purified by column chromatography on silica (elution with 5:1 hexane:ethyl acetate)