Ding Derong, Zhao Cong-Gui, Guo Qunsheng, Arman Hadi
Department of Chemistry, University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249-0698, USA.
Tetrahedron. 2010 Jun 19;66(25):4423-4427. doi: 10.1016/j.tet.2010.04.044.
Bicyclo[3.2.1]octan-8-ones have been prepared from a tandem Michael-Henry reaction between cyclohexane-1,2-diones and nitroalkenes using a quinine-derived thiourea as the catalyst. Although four stereogenic centers were created during the reaction, only two diastereomers were obtained in good diastereoselectivity and high enantioselectivity (92-99% ee). When 3-methylcyclohexane-1,2-dione (R(1) = Me) was used as the substrate, only the regioisomeric product of the corresponding thermodynamic enolate was obtained.
双环[3.2.1]辛烷-8-酮是通过环己烷-1,2-二酮与硝基烯烃之间的串联迈克尔-亨利反应制备的,使用奎宁衍生的硫脲作为催化剂。尽管反应过程中产生了四个立体中心,但仅以良好的非对映选择性和高对映选择性(对映体过量92-99%)得到了两种非对映异构体。当使用3-甲基环己烷-1,2-二酮(R(1) = 甲基)作为底物时,仅得到了相应热力学烯醇盐的区域异构体产物。