Diels-Alder reactions between dienamides and quinones: Stereochemistry of the cycloadditions and cytotoxic activity of the adducts.
作者:Mohamed CHIGR、Houda FILLION、Annie ROUGNY、Maryse BERLION、Jacqueline RIONDEL、Helene BERIEL
DOI:10.1248/cpb.38.688
日期:——
tetrahydroanthraquinones bearing an amido group have been prepared by Diels-Alder reactions between (E)-1-(N-carbobenzyloxyamino)-1,3-butadiene (2) or (E)-1-(N-benzoyl-N-benzylamino)-1,3-butadiene (5) and benzoquinone or 5-substituted naphthoquinones. The stereochemistry of the cycloadditions was investigated. A high regioselectivity was observed in the reaction of the diene carbamate 2 with 5-methoxy and 5-acetoxy
带有酰胺基的四氢萘醌和四氢蒽醌是通过(E)-1-(N-羰基苄氧基氨基)-1,3-丁二烯(2)或(E)-1-(N-苯甲酰基-N-苄基氨基)-1,3-丁二烯(5)和苯醌或5个取代的萘醌。研究了环加成的立体化学。在氨基甲酸二烯2与5-甲氧基和5-乙酰氧基萘醌的反应中观察到高的区域选择性。后者给出了出乎意料的1,8-区域异构体3d。二烯酰胺5与萘醌1(R = OH,OMe,OAc)的环加成是区域特异性的。四氢蒽醌6b的结构分配与在类似的Diels-Alder反应中juglone 1b的5-羟基的已知导向作用很好地吻合。与5-甲氧基和5-乙酰氧基萘醌一起,观察到的相反的区域化学与甲氧基或乙酰氧基的供电子作用相一致,从而使C-3碳原子更缺乏电子。加合物6b和7c的芳香化伴随着酰胺基团的不寻常消除。因此,获得了1-羟基和1-甲氧基蒽醌。二烯2和5与苯醌的反应得到具有内立体定向性的四氢萘醌9和10。活化的