Photochemische Cycloadditionen von 3-Phenyl-2<i>H</i>-azirinen mit Ketonen, Acylcyaniden und Ketoestern. 33. Mitteilung über Photoreaktionen
作者:Peter Claus、Paul Gilgen、Hans-Jürgen Hansen、Heinz Heimgartner、Barry Jackson、Hans Schmid
DOI:10.1002/hlca.19740570732
日期:1974.11.6
Similarly to aldehydes [6] ketones form 3-oxazolines via cyclo-addition to the benzonitrile-methylides 2 that arise photochemically from the 3-phenyl-2H-azirines 1. With various ketones benzonitrile-isopropylide (2a) gives cyclo-addition products in very good preparative yields (scheme 1). Benzonitrile-ethylide (2c) and benzonitrile-benzylide (2b) [8] react, however, sluggishly with ketones, smooth
与醛类似,[6]酮通过环加成苯并腈-甲基化物2形成3-恶唑啉,该苯甲腈-甲基化物2从光化学上由3-苯基-2 H-叠氮基1生成。用各种酮,苯甲腈-异丙基化物(2a)以非常好的制备产率(方案1)提供环加成产物。苯甲腈-乙(2c)和苯甲腈-苄基(2b)[8]反应缓慢,但与酮反应缓慢,仅在与“活化”酮(2,2,2-三氟苯乙酮, 1,1,1-三氟-2-丙酮)。与1a的丙酮基丙酮形成双加合物12