endo-[4+2] cycloadducts, the kinetically controlled products, at 3000 bar. In the latter case, the product further reacted with tropone to yield 2:1-adducts. On the other hand, the reaction with 3,4-dimethoxyfuran under similar conditions yielded mainly the exo-[4+2] adducts, the thermodynamically controlled products. The predominant formation of the endo-Diels–Alder adducts with furans under the high-pressure
在 3000 巴下,托酮与
呋喃和 2-甲氧基
呋喃的热反应主要产生内-[4+2] 环加合物,即动力学控制的产物。在后一种情况下,产物进一步与托酮反应生成 2:1-加合物。另一方面,在类似条件下与 3,4-二甲氧基
呋喃的反应主要产生外型-[4+2] 加合物,即热力学控制的产物。从合成的角度来看,在高压条件下与
呋喃形成的内狄尔斯-阿尔德加合物的主要形成可能是有价值的。