反应详情

温度

-70 °C

n-Butyllithium (0.37 mL, 0.59 mmol, 1.6 M in hexanes) was added dropwise over 5 min to a solution of 3,4,5-trimethoxybenzylphosphonium bromide (0.27 g, 0.52 mmol) in THF (3 mL) at −10° C. The reaction mixture was stirred at this temperature for 15 min then cooled to −70° C. and a solution of 41 (0.10 g, 0.24 mmol) in THF (3 mL) was added and the reaction mixture was allowed to warm to rt with stirring overnight (16 h). The reaction mixture was cooled to 0° C. and water was added. The reaction mixture was extracted with t-BuOMe (3×) and the organic phase was washed successively with water and brine, dried (Na2SO4) and evaporated to dryness to give crude product (0.3 g). Purification by column chromatography (SiO2 2:98 EtOAc:cyclohexane) gave 42 (83 mg, 60%) as an 85:15 mixture of Z:E isomers.

1. temperatureto warm to rt
2. stirringwith stirring overnight (16 h)
3. temperatureThe reaction mixture was cooled to 0° C.
4. extractionThe reaction mixture was extracted with t-BuOMe (3×)
5. washthe organic phase was washed successively with water and brine
6. dry with materialdried (Na2SO4)
7. customevaporated to dryness
8. customto give crude product (0.3 g)
9. customPurification by column chromatography (SiO2 2:98 EtOAc:cyclohexane)