Photochemische Cycloadditionen von 3-phenyl-2<i>h</i>-azirinen mit Aldehyden. 31. Mitteilung über Photoreaktionen
作者:Heinz Giezendanner、Heinz Heimgartner、Barry Jackson、Tammo Winkler、Hans-Jürgen Hansen、Hans Schmid
DOI:10.1002/hlca.19730560745
日期:1973.11.7
Experiments concerning the photochemical condensation of 3-phenyl-2H-azirines 1 with aliphatic and aromatic aldehydes to 3-oxazolines 4 are fully described (cf. scheme 1). Photochemically nitrile methylides of type 2 are first formed, which then very quickly react thermally with the aldehydes in a regiospecific manner to give the 3-oxazolines 4. Azirines monosubstituted in position 2 (lb and 1c) give
关于3-苯基2的光化学缩合实验ħ -azirines 1与脂肪族和芳香族醛-3-恶唑啉4中充分描述(CF。方案1)。首先形成光化学类型为2的腈亚甲基,然后以区域特异性方式非常快速地与醛进行热反应,生成3-恶唑啉4。在位置2(l b和1 c)上单取代的嗪生成顺式,反-恶唑啉异构体的混合物,其中顺式异构体占主导地位。环加成反应的立体选择性可以通过简单的模型来合理化(方案10)。