Base catalysed rearrangements involving ylide intermediates. Part 4. [1,3] Sigmatropic rearrangements of 4-dimethylaminobutenes and [3,3] sigmatropic rearrangements of 3-dimethylaminohexa-1,5-dienes
作者:Robert W. Jemison、W. David Ollis、Ian O. Sutherland、James Tannock
DOI:10.1039/p19800001462
日期:——
3] sigmatropic rearrangement (11)→(12) of the 9-dimethylamino-9-(1-phenylallyl)fluorene is a stereoselective process (84 : 16) at 170°. Analogous [1,3] rearrangements (16)→(17) of other fluorene derivatives show that the reaction rate is increased by electron donating 9-substituents in the order O– > NMe2 > OMe. Similar substituent effects are observed for the [3,3] Cope rearrangement (25)→(26) of hexa-1
9-二甲基氨基-9-(1-苯基烯丙基)芴的[1,3]σ重排(11)→(12)是170°的立体选择过程(84:16)。其他芴衍生物的类似[1,3]重排(16)→(17)显示,通过给电子9-取代基的顺序为O – > NMe 2 > OMe ,反应速率得到了提高。对于六-1,5-二烯的[3,3]上交重排(25)→(26),观察到类似的取代基作用。4-苯基,4,4-二甲基和3-二甲基氨基取代基在加速重排(25)→(26)的速率方面特别有效。