E-α,β-Unsaturated ketones can be obtained with complete E-selectivity by a sequential reaction of dichloroketones with a variety of aldehydes. This transformation was promoted by SmI2, SmI2 in the presence of FeCl3 or CrCl2. The best results were obtained when CrCl2 was used as the metallating agent. A mechanism based on a successive aldol-type reaction and a β-elimination is proposed to explain these results.
通过二
氯酮与各种醛的连续反应,可以得到具有完全E选择性的E-α,β-不饱和酮。
SmI2、 在 FeCl3 或 CrCl2 存在下促进了这种转化。当使用CrCl2作为
金属化剂时获得了最好的结果。提出了基于连续羟醛型反应和β-消除的机制来解释这些结果。