A Facile Synthetic Route to 2H-Chromenes: Reconsideration of the Mechanism of the DBU-Catalyzed Reaction between Salicylic Aldehydes and Ethyl 2-Methylbuta-2,3-dienoate
作者:Lun-Zhi Dai、Yong-Ling Shi、Gui-Ling Zhao、Min Shi
DOI:10.1002/chem.200601033
日期:2007.4.27
Reactions of salicylaldehydes with ethyl buta-2,3-dienoate or penta-3,4-dien-2-one catalyzed by a catalytic amount of potassium carbonate produce the corresponding 2 H-chromene products in moderate to good yields under mild conditions. A plausible reaction mechanism is discussed in the light of the results of an 18O-labeling experiment. In addition, in view of these findings, the catalytic function
水杨醛与催化量的碳酸钾催化的丁酸2,3-丁二酸乙酯或戊基3,4-二烯-2-戊酯的反应在温和的条件下以中等至良好的产率产生了相应的2 H-色烯产物。根据18O标记实验的结果,对合理的反应机理进行了讨论。另外,鉴于这些发现,重新考虑了DBU在这种反应中的催化功能。