The acid-catalyzed condensation of aldehydes and acetamide has been shown to provide a pool of diverse equilibrating species. For the first time, the synthesis of substituted 1-N-acylamino-1,3-butadienes has been accomplished directly in moderate yields upon telomerization of two molecules of aldehyde with one molecule of carboxamide. Detailed spectroscopic and computational investigations establish the favourable formation of all-trans aminodienes under the reaction conditions. Employment thereof as diene building blocks in DielsâAlder reactions allows for the synthesis of carbocyclic molecules with high stereocontrol.
事实证明,酸催化的醛和乙
酰胺缩合反应可提供多种平衡物质。在两分子醛与一分子羧
酰胺发生端聚反应后,首次以中等产率直接合成了取代的 1-
N-乙酰
氨基-
1,3-丁二烯。详细的光谱和计算研究证实,在反应条件下有利于形成全反式
氨基二
烯。在 DielsâAlder 反应中将其用作二
烯结构单元,可以合成具有高度立体控制的
碳环分子。