反应详情

Under argon, tetrakis(triphenylphosphine)palladium(0) (19 mg, 0.02 mmol) was initially charged in a round-bottom flask that had been dried by heating, and abs. tetrahydrofuran (5 ml) and 8-ethynyl-2,3,7,9-tetramethyl-9-(trifluoromethyl)-1,4-dioxaspiro[4.5]dec-6-en-8-ol (100 mg, 0.33 mmol) were added. Stirring at room temperature for 5 minutes was followed by the addition of tributyltin hydride (0.11 ml, 0.39 mmol). The resulting reaction mixture was stirred at 55° C. for 1 h and, after cooling to room temperature, water was added. The aqueous phase was repeatedly extracted thoroughly with dichloromethane, and the combined organic phases were then dried over magnesium sulfate, filtered and concentrated under reduced pressure. By final column chromatography purification of the resulting crude product (ethyl acetate/heptane gradient), it was possible to obtain 2,3,7,9-tetramethyl-8-[(E)-2-(tributylstannyl)vinyl]-9-(trifluoromethyl)-1,4-dioxaspiro[4.5]dec-6-en-8-ol (160 mg, 82% of theory) in the form of a colorless oil. 1H-NMR (400 MHz, CDCl3 δ, ppm) 6.33/6.31 (d, 1H), 5.97/5.92 (d, 1H), 5.51/5.42 (s, 1H), 4.24/3.64 (m, 2H), 2.46/2.35 (d, 1H), 1.92 (br. s, 1H, OH), 1.91/1.87 (d, 1H), 1.64/1.62 (s, 3H), 1.49 (m, 6H), 1.32-1.26 (m, 9H), 1.18 (m, 3H), 0.89 (m, 18H).

1. customhad been dried
2. temperatureby heating
3. customThe resulting reaction mixture
4. stirringwas stirred at 55° C. for 1 h
5. temperatureafter cooling to room temperature
6. extractionThe aqueous phase was repeatedly extracted thoroughly with dichloromethane
7. dry with materialthe combined organic phases were then dried over magnesium sulfate
8. filtrationfiltered
9. concentrationconcentrated under reduced pressure
10. customBy final column chromatography purification of the resulting crude product (ethyl acetate/heptane gradient), it