Highly stereoselective construction of spiro[cyclopropane-1,4′-pyrazolin-5′-one]with 4-arylidene-3-methyl-1-phenyl-pyrazolin-5-one and arsonium ylide
作者:Zhongjiao Ren、Weiguo Cao、Jie Chen、Yali Chen、Hongmei Deng、Min Shao、Danyi Wu
DOI:10.1016/j.tet.2008.03.049
日期:2008.5
A highly stereoselective synthesis of exo-spiro[cyclopropane-1,4′-pyrazolin-5′-one] from 4-arylidene-3-methyl-1-phenyl-pyrazolin-5-one and arsonium bromide in the presence of base has been achieved. The triphenylarsine-catalyzed cyclopropanation of 4-arylidene-3-methyl-1-phenyl-pyrazolin-5-one with bromide in the presence of NaHCO3 has also been studied. Both exo and endo isomers were formed in this
在碱存在下,由4-亚芳基-3-甲基-1-苯基-吡唑啉-5-酮和溴化砷高度立体选择性地合成exo -spiro [cyclopropane-1,4'-pyrazolin-5'-one]实现了。在NaHCO 3存在下,还研究了三苯ar催化四溴化亚芳基-3-甲基-1-苯基-1-吡唑啉-5-酮的环丙烷化反应。两个外和内切形成在该反应中的异构体。产物的结构通过IR,MS,1 H NMR,元素分析和X射线衍射分析来表征。