反应详情

温度

25 °C

To a solution of crotonaldehyde (31.8 g, 0.454 mole) and triethylamine (51.4 g, 1.1 eq) in benzene at 25° C., was added hydroquinone (0.95 g) and zinc chloride (0.75 g) rapidly with efficient stirring. This was followed by the addition of freshly distilled trimethylsilyl chloride (46 ml, 0.9 eq) over 1-2 minutes, whereupon a white precipitate rapidly formed. After stirring the mixture for 30 minutes at 25° C., a further 0.2 eq of trimethylsilyl chloride were added. The reaction was then warmed to 70° C. and stirred at this temperature for 12 hours. It was then cooled to 0° C., quenched by addition of saturated aq. NaHCO3 (75 ml), poured into a separatory funnel, and the organic layer separated. The aqueous layer was extracted with further portions of benzene (3×50 ml), the organic extracts combined, washed with 10% KHSO4, and the benzene removed in vacuo to leave a dark brown liquid. Distillation through a short Vigreaux column yielded 28.4 g (46%) of pure 1-trimethylsilyloxy-1,3-butadiene as a colorless liquid (bp 78°-80° C./68 mm Hg). 1H NMR (200 MHz, CDCl3): δ 6.66(1H,d,J=11.9 Hz), 6.35(1H,dt,J=17.1, 10.6Hz), 5.84(1H,t,J=11.4 Hz), 5.11(1H,dd,J=16.8, 1.8 Hz), 4.94(1H,dd,J=10.3, 1.8 Hz), 0.37(9H, s).

1. customrapidly formed
2. temperatureThe reaction was then warmed to 70° C.
3. stirringstirred at this temperature for 12 hours
4. temperatureIt was then cooled to 0° C.
5. customquenched by addition of saturated aq. NaHCO3 (75 ml)
6. additionpoured into a separatory funnel
7. customthe organic layer separated
8. extractionThe aqueous layer was extracted with further portions of benzene (3×50 ml)
9. washwashed with 10% KHSO4
10. customthe benzene removed in vacuo
11. customto leave a dark brown liquid
12. distillationDistillation through a short Vigreaux column