反应详情

温度

-78 °C

A mixture of methyltriphenylphosphonium bromide (12.27 g) and anhydrous tetrahydrofuran (60.0 mL) was cooled to −78° C. A suspension of potassium t-butoxide (4.37 g) in tetrahydrofuran (60.0 mL) was added dropwise. The mixture was stirred at 0° C. for 1 hour and then for 1 hour as the reaction warmed to ambient temperature. The reaction mixture was cooled to −40° C. and a solution of EXAMPLE 341D (5 g,) in tetrahydrofuran (35 mL) was added dropwise. After stirring 18 hours at ambient temperature, the reaction was quenched by the careful addition of 33% brine (150 mL) and diluted with ether (150 mL). The layers were separated and the aqueous layer was extracted with ether (2×75 mL). The combined organics were dried over sodium sulfate, filtered and concentrated. The residue was purified on silica gel and eluted with a 0, 10, 15, 25% ethyl acetate in hexane step gradient to provide the title compound.

1. additionwas added dropwise
2. temperaturefor 1 hour as the reaction warmed to ambient temperature
3. temperatureThe reaction mixture was cooled to −40° C.
4. stirringAfter stirring 18 hours at ambient temperature
5. customthe reaction was quenched by the careful addition of 33% brine (150 mL)
6. additiondiluted with ether (150 mL)
7. customThe layers were separated
8. extractionthe aqueous layer was extracted with ether (2×75 mL)
9. dry with materialThe combined organics were dried over sodium sulfate
10. filtrationfiltered
11. concentrationconcentrated
12. customThe residue was purified on silica gel
13. washeluted with a 0, 10, 15, 25% ethyl acetate in hexane step gradient