反应详情

Under argon, tetrakis(triphenylphosphine)palladium(0) (231 mg, 0.20 mmol) was initially charged in a round-bottom flask that had been dried by heating, and abs. tetrahydrofuran (25 ml) and 8-ethynyl-2,3,7,9,9-pentamethyl-1,4-dioxaspiro[4.5]dec-6-en-8-ol (1.0 g, 3.99 mmol) were added. Stirring at room temperature for 5 minutes was followed by the addition of tributyltin hydride (1.29 ml, 4.79 mmol). The resulting reaction mixture was stirred at room temperature for 1 h and then 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 2,3,7,9,9-pentamethyl-8-[(E)-2-(tributylstannyl)vinyl]-1,4-dioxaspiro[4.5]dec-6-en-8-ol (1.50 g, 66% of theory) in the form of a colorless oil. 1H-NMR (400 MHz, CDCl3 δ, ppm) 6.13 (d, 1H), 5.93 (d, 1H), 5.42 (s, 1H), 4.22/3.63 (m, 2H), 1.61 (s, 3H), 1.59 (d, 1H), 1.52 (d, 1H), 1.49 (m, 6H), 1.32-1.24 (m, 12H), 1.09 (s, 3H), 0.89 (m, 18H).

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