Reduction of 4,5-Dihydro-1,2-oxazoles (Δ<sup>2</sup>-Isoxazolines); A Cycloadditive Approach to 2-Alkenyl Ketones
作者:Dennis P. Curran、Byeang Hyean Kim
DOI:10.1055/s-1986-31595
日期:——
A new cycloadditive route to 2-alkenyl ketones (β,γ-unsaturated ketones) involves: (1) nitrile oxide-allylsilane (or stannane) cycloaddition, (2) reductive cleavage of the resultant isoxazoline, and (3) Peterson elimination. In all cases, the products art: not contaminated by the isomeric 1-alkenyl ketones. Although stereoselectivity in the nitrile oxide cycloaddition to 3-trimethylsilyl-1-butene is low, the resultant diastereomeric cycloadducts can be converted stereospecifically to the corresponding (E)- and (Z)-olefins.
2- 烷基酮(δ,δ³-不饱和酮)的新环加成路线包括:(1) 氧化腈-烯丙基硅烷(或锡烷)环加成,(2) 还原裂解生成的异噁唑啉,以及 (3) 彼得森消除。在所有情况下,产物都不会受到异构 1-烯基酮的污染。 虽然氧化腈与 3-三甲基硅基-1-丁烯的环加成反应的立体选择性较低,但由此产生的非对映异构环加成产物可以立体定向地转化为相应的 (E)- 烯烃和 (Z)- 烯烃。