Mechanistic insights into the rearrangement of azetidine N-oxides to isoxazolidines
作者:Laurence Menguy、Bruno Drouillat、Jérome Marrot、François Couty
DOI:10.1016/j.tetlet.2012.06.092
日期:2012.8
Meisenheimer rearrangement. This ring expansion leading to isoxazolidines occurs readily, without trapping of the transient N-oxide. Starting with azetidines bearing a nitrile or an ester group at C-2, the rearrangement is regioselective. However, a varying amount of epimerization on the migrating radical is observed, which can also be observed with the related [1,2] Stevens rearrangement.
各种官能氮杂环丁烷用氧化米CPBA或过氧化氢,以产生相应的N-氧化物,在[1,2]迈森海梅重排研究其命运。这种导致异恶唑烷的环膨胀很容易发生,而不会捕获瞬态N-氧化物。从在C-2处带有腈或酯基的氮杂环丁烷开始,重排是区域选择性的。但是,在迁移的自由基上观察到不同数量的差向异构化,这也可以通过相关的[1,2]史蒂文斯重排观察到。