Sodium dithionite initiated reactions of 1-bromo-1-chloro-2,2,2-trifluoroethane with enol ethers of cyclic ketones
作者:Wojciech Dmowski、Jolanta Ignatowska
DOI:10.1016/s0022-1139(03)00007-1
日期:2003.9
Sodium dithionite initiated reactions of 1-bromo-1-chloro-2,2,2-trifluoroethane (1) with methyl and trimethylsilyl ethers of cyclopentanone and cyclohexanone enols (2a–d) in a MeCN/H2O system were investigated. 2-(2,2,2-Trifluoroethylidene)cyclopentanone (4a) and 2-(2,2,2-trifluoroethylidene)-cyclohexanone (4b), respectively, were obtained as the main products and isolated in reasonable yields. The
在MeCN / H 2 O系统中,研究了连二亚硫酸钠引发的1-溴-1-氯-2,2,2-三氟乙烷(1)与环戊酮和环己酮烯醇(2a - d)的甲基和三甲基甲硅烷基醚的反应。以主要产物形式获得2-(2,2,2-三氟亚乙基)环戊酮(4a)和2-(2,2,2-三氟亚乙基)-环己酮(4b),并以合理的产率分离。与5-和3-甲基取代的1-甲氧基环己烯,2e和2f的1:1混合物反应,显示出位阻对反应速率的强烈影响。2-(2,2,2-三氟亚乙基)-5-甲基环己酮的混合物(6),以9:1的比例形成2-(2,2,2-三氟亚乙基)-3-甲基环己酮(7)。将酮4a和4b还原为相应的醇8和9,并且4b与肼的反应得到吲唑衍生物10。