Nafion-TMS- and TMS-Trifluoroacetate-Induced Rearrangements of Cyclopropyl Ketones - A procedure for the regioselective conversion of semibullvalenes to barrelenes
作者:Martin Demuth、Gamal Mikhail、Manapurathu V. George
DOI:10.1002/hlca.19810640837
日期:1981.12.16
modes in the opening of cyclopropyl ketones. The yields are generally high. Nafion-TMS rearranges the tricyclooctanones 1a and 1b to the bicyclooctenones 4a and 4b (while TMSTFA gives ring-opened adducts 6a,b) with high regioselectivity. Aro-semibullvalenes (8a, 14, 17a,b) are efficiently rearranged to arobarrelenes (7a, 13, 20a,b) by both reagents. The latter rearrangements have also been achieved
三氟乙酸三甲基甲硅烷基酯(TMSTFA)和聚合物负载的磺酸盐Nafion -TMS在打开环丙基酮中表现出选择性的反应模式。产量通常很高。Nafion -TMS以高区域选择性将三环辛酮1a和1b重排为双环辛烯4a和4b(而TMSTFA提供开环的加合物6a,b)。芳香半牛戊烯(8a, 14、17a ,b)被有效地重排为芳香戊烯(7a, 13、20a ,b)两种试剂。后者的重排也已在三氟乙酸和四甲基硅烷(TMS)的混合物中实现,其中该酸与商业TMS的未鉴定杂质结合形成强亲电试剂。萘-半bullvalenes 14a + b的亲电辅助重排导致转化为萘桶型烯13a + b,其区域选择性与在220°C下热平衡所观察到的区域选择性相反。