3-Hydroxypyrroles and 1H-pyrrol-3(2H)-ones. Part 14.1,2 Pyrolysis of oxazolidinylmethylene derivatives of Meldrum's acid – synthesis of N-alkenyl-3-hydroxypyrroles and related reactions
作者:Abd El-Aal M. Gaber、Gordon A. Hunter、Hamish McNab
DOI:10.1039/b109788a
日期:2002.2.6
Flash vacuum pyrolysis (FVP) of the title compounds 14 and 17 at 600–625 °C (0.005 Torr) gives the N-alkenylpyrrolones 22 and 23 respectively. The mechanism is shown to involve hydrogen transfer and cyclisation of the methyleneketene intermediate (e.g.25) to a fused pyrrolone (e.g.28). This species fragments to create an azomethine ylide which provides the alkenyl substituent by a further hydrogen
闪蒸真空热解 (最有价值球员)的标题化合物14和17在600–625°C(0.005托)下分别得到N-烯基吡咯烷酮22和23。结果表明该机制涉及氢转移和环化将亚甲基烯酮中间体(例如25)转化为稠合的吡咯烷酮(例如28)。这个物种碎片创造了一个甲亚胺叶立德 提供 烯基通过进一步的氢转移取代基。类似的反应由噻唑烷派生20和21,尽管在后一种情况下,最初的自行车35和37 可以通过核磁共振波谱。当正常的氢转移位点被取代基所阻挡时(如化合物16所示),另一种氢转移-环加成序列导致融合的吡啶-4-酮43。