Reactions of the Hydrofluoroborate Salts of Open-Chain Analogues of Reissert Compounds with Some α,β-Ethylenic Esters
作者:Sandrine Perrin、Karin Monnier、Bernard Laude、Marek Kubicki、Olivier Blacque
DOI:10.1002/(sici)1099-0690(199901)1999:1<297::aid-ejoc297>3.0.co;2-j
日期:1999.1
The reaction of the hydrofluoroborate salt of an open-chain analogue of a Reissert compound with some α,β-ethylenic esters does not give a [4 + 2] cycloadduct, as previously described in the case of ethyl acrylate. The reaction starts with a 1,3-dipolar cycloaddition of a munchnone imine 5c, d. The [3 + 2] cycloadducts 13 evolve via a rearrangement–condensation sequence to give a substituted 2-pyridone
Reissert 化合物的开链类似物的氢氟硼酸盐与一些 α,β-乙烯酯的反应不会产生 [4 + 2] 环加合物,如先前在丙烯酸乙酯的情况下所述。该反应以munchnone亚胺5c、d的1,3-偶极环加成开始。[3 + 2] 环加合物 13 通过重排 - 缩合序列演变为取代的 2-吡啶酮衍生物 18 或 19。所提出的机制已通过反应序列中一些化合物的分离和结构 X 射线分析得到验证。