Carbanions derived from cyclic 1,3-dicarbonyl compounds reacted smoothly with some vinyl bromides and 1,3-enones in HMPA in the presence of copper(I) iodide to give geminally disubstituted alkanes in good yields. The products were easily dehydrated intramolecularly to form 4H-pyran derivatives almost quantitatively.
在
碘化
铜 (I) 存在下,源自环状 1,3-二羰基化合物的碳负离子与一些
乙烯基溴化物和 1,3-烯酮在 HMPA 中顺利反应,以良好的产率得到孪位双取代的
烷烃。产物很容易在分子内脱
水以几乎定量地形成
4H-吡喃衍
生物。