Thermal isomerization of 1-morpholino-3-phenyl (or vinyl)-allenes: synthesis of the [1,4]oxazino-[4,3-a]azepine framework
作者:Theo Mayer、Gerhard Maas
DOI:10.1016/0040-4039(92)88051-6
日期:1992.1
1-Morpholino-3-phenylallenes isomerize to 3,4,6,12b-tetrahydro-1H-[1,4]oxazino[4,3-a][2]benzazepines at ≥ 105 °C. Similarly, 1-morpholino-3-vinylallenes are transformed into 3,4,10,10a-tetrahydro-1H-[1,4]oxazino[4,3-a]azepines. Formation of these novel heterocycles is rationalized by a 1,3-proton shift in the morpholinoallenes, followed by 1,7-electrocyclization of the α,β,γ,δ-unsaturated azomethine
1-Morpholino-3-phenylallenes在≥105°C时异构化为3,4,6,12b-四氢-1 H- [1,4]恶嗪基[4,3-a] [2]苯并ze庚因。类似地,将1-吗啉代-3-乙烯基烯丙基转化为3,4,10,10a-四氢-1 H- [1,4]恶嗪基[4,3-a]氮杂。这些新杂环的形成可通过吗啉代烯丙烯中的1,3-质子移位来合理化,然后对如此形成的α,β,γ,δ-不饱和甲亚胺叶立德进行1,7-电环化。