A Mild and Efficient Procedure for Asymmetric Michael Additions of a-Bromochalcone with Cyclohexanone Catalyzed by Different Bases
作者:Li-Guo Gao、Dong-Zhi Liu、Wei Li、Xue-Qin Zhou
DOI:10.14233/ajchem.2013.13457
日期:——
A mild and efficient procedure for Michael addition of a-bromochalcone with cyclohexanone has been developed. In the presence of sodium ethoxide, a-bromochalcone reacted with cyclohexanone to afford Michael products in moderate to high yield and good diastereoselectivities. Especially, while CH3CH2ONa or t-BuOK as catalyst, the unexpected products were obtained, which were the compound 4a((8aR,9S)-4a,8a-dihydroxy-10-phenyl-tetradecahydro-phenanthren-9-yl)(phenyl)methanone) and 4b(((8aR,9R)-4a,9-dihydroxy-10-phenyl-tetradecahydrophenanthren-9-yl)(phenyl)methanone).
研究人员开发出了一种温和、高效的方法,用于 a-bromochalcone 与环己酮的迈克尔加成反应。在乙醇钠存在下,a-溴查耳酮与环己酮反应生成迈克尔产物,产率从中度到高度不等,非对映选择性良好。特别是以 CH3CH2ONa 或 t-BuOK 为催化剂时,得到了意想不到的产物,即化合物 4a((8aR,9S)-4a,8a-二羟基-10-苯基-十四氢菲-9-基)(苯基)甲酮)和 4b(((8aR,9R)-4a,9-二羟基-10-苯基-十四氢菲-9-基)(苯基)甲酮)。