ring-opening accompanies adduction to give 11 and two stereoisomers of gross structure 12. Dienes 1, 9 (X = OMe) and 9 (X = H) react at similar rates with N-methylmaleimide, discounting the alleged intramolecular retardation due to through space interaction between the hydroxy group and the diene system.
与早先的观察相反,二烯1在Diels-Alder添加物中容易反应。用N-甲基马来
酰亚胺等量地形成立体异构加合物10a和10b。在
顺丁烯二酸酐的情况下,开环伴随加成得到11和两个总体结构12的立体异构体。二烯1,9(X = OMe)和9(X = H)与N-甲基马来
酰亚胺的反应速率相似,从而消除了所谓的分子内阻滞作用。由于羟基和二烯系统之间通过空间相互作用。