Synthesis and characterization of bis-cyclopropanated 1,3,5-tricarbonyl compounds. A combined synthetic, spectroscopic and theoretical study
作者:Thomas Rahn、Franziska Bendrath、Martin Hein、Wolfgang Baumann、Haijun Jiao、Armin Börner、Alexander Villinger、Peter Langer
DOI:10.1039/c1ob05455d
日期:——
Bis-cyclopropanated 1,3,5-tricarbonyl compounds were prepared by a sequence of Claisen condensations and cyclopropanations. The optimization of the conditions proved to be very important to suppress retro-Claisen reactions. The conformation of these molecules was studied by experimental and computational methods. The syn/syn;syn/syn conformation is present for all derivatives. It is exclusively present in the case of the derivative containing a phenyl group located at the terminal carbon atom. In most cases, equilibria with other conformers are found.
双环丙烯化的1,3,5-三羰基化合物是通过一系列克莱森缩合反应和环丙烯化反应制备的。优化反应条件被证明对抑制逆克莱森反应非常重要。这些分子的构象通过实验和计算方法进行了研究。所有衍生物均呈现出syn/syn;syn/syn构象。在含有位于末端碳原子的苯基的衍生物中,该构象是独占性的。在大多数情况下,还发现与其他构象体的平衡。