Diels-Alder transformation of substituted 3-benzoylamino-2H-pyran-2-ones 1 with a variety of alkynes 2 under microwave (MW) irradiation in a closed system can be intensified in a novel way by addition of a minor amount of butan-1-ol. When the reagents are not volatile under the used conditions, the reactions do not seem to be influenced by the addition of butan-1-ol, as demonstrated by the cycloaddition of a fused 2H-pyran-2-one 5 with N-ethylmaleimide (6) giving adduct 7.
用微波(MW)辐射在封闭系统中对取代的3-苯甲酰
氨基-2
H-
吡喃-2-酮
1 与多种
炔烃 2 进行 Diels-Alder 变换,通过添加少量
丁醇可以以一种新颖的方式加强反应。当试剂在所用条件下不挥发时,添加
丁醇似乎不会影响反应,这由融合的2
H-
吡喃-2-酮
5 与
N-乙基马来
酰亚胺 (
6) 发生的环加成反应,生成产物
7 所证明。