2,2,3,3-四甲基-7a-R-1,2,3,7a-四氢咪唑并[1,2 - b ]异恶唑-6,7-二羧酸酯衍生物的异常热转变
摘要:
二甲基2,2,3,3-四甲基-7a-R-1,2,3,7a-四氢咪唑并[1,2- b ]-异恶唑-6,7-二羧酸酯衍生物沿两种竞争路线进行热重排生成2-(2-R-4,5-二氢-1 H -3λ-5-咪唑-3-亚甲基)-3-氧代琥珀酸酯衍生物和(或)二甲基-2-氧代-3-(1- R-咪唑啉丁-2-亚基)琥珀酸酯。在N-未取代的衍生物的情况下,后者进行分子内环化,生成甲基5,6-二氧-1--1-R-2,3,5,6-四氢-1 H-吡咯并[1,2 - a ]咪唑-7 -羧酸盐。
Mechanism of the migration of the substituent in 1,2,3,7a-tetrahydroimidazo[1,2-b]isoxazole derivatives
作者:N. V. Chukanov、S. A. Popov、T. N. Drebushchak、V. A. Reznikov
DOI:10.1007/s11172-010-0318-6
日期:2010.9
intramolecular rearrangements by two main pathways. One rearrangement affords azomethine ylide derivatives. Another rearrangement leads to the migration of the substituent from position 7a to the nitrogen atom. The rate constants of these reactions were determined. Quantum chemical calculations by the DFT method were carried out. Based on the data for the migration of the substituent, the concerted mechanism