Stereoselective synthesis of (Z)-methyl 3-perfluoroalkyl-4-substitutedphenylbutenoates
作者:Ding Weiyu、Pu Jiaqi、Zhang Chunming、Cao Weiguo
DOI:10.1039/p19910001369
日期:——
-triphenylphosphoranylidenebut-2-enoates, 7a–o. Compounds 6a–o exists as pairs of E/Z isomers, the ratios are 2 : 1 for RF= CF3, and 3 : 1 for RF= C2F5 or C3F7. Compounds 7a–o are transformed into 6a–o when heated. (Z)-Methyl 3-perfluoroalkyl-4-substituted-phenylbut-3-enoates 8a–o can be obtained stereoselectively in high yield when an aqueous methanol solution of mixed 6a–o and 7a–o was heated for
研究了(Z)-3-全氟烷基-4-取代的苯基丁-3-烯酸酯甲基(8)-o的立体选择性合成。在室温下,在K 2 CO 3存在下,取代的苄基三苯基溴化5 5a – e与2-全氟烷基甲基丙烯酸2a – c的反应。给出了两个加合物,3-全氟烷基-4-取代的苯基-2-亚苯基正膦亚基丁基-3-烯酸酯甲基,6a – o和3-全氟烷基-4-取代的苯基-4-三苯基亚苯基丁烯-2-丁烯酸酯,甲基丙烯酸7a – o。化合物6a– o以E / Z异构体对形式存在,R F = CF 3的比率为2 :1,R F = C 2 F 5或C 3 F 7的比率为3:1 。加热时,化合物7a – o转变为6a – o。当混合有6a - o和7a-的甲醇水溶液时,可以高选择性地立体选择性地制得(Z)3-全氟烷基-4-取代的苯基丁-3-烯酸甲酯8a - o。o加热10–20小时。