A series of highly reactive cyclopentadienones were prepared in situ from the corresponding hydroxycyclopent-2-enones and trapped with a variety of quinones. Reaction of 1,4-naphthoquinone with 4-hydroxy-3,4-diphenyl-cyclopent-2-enone afforded 2,3-diphenylanthraquinone, whereas reaction of benzoquinone with this same cyclopentadienone precursor yielded a mixture of 6,7-diphenyl-1,4-naphthoquinone and 2,3,6,7-tetraphenyl anthraquinone. A number of other 2,3-diarylanthraquinones were likewise prepared in moderate yields from the reaction of 1,4-naphthoquinone with the appropriate 4-hydroxy-3,4-diarylcyclopent-2-enones. This method appears to be generally applicable to the synthesis of anthraquinone derivatives substituted at the 2- and 3-positions from inexpensive starting materials.Key words: anthraquinone, DielsAlder, cyclopentadienone, in situ.
从相应的羟基环戊-2-烯酮原位制备了一系列高活性
环戊二烯酮,并与多种
醌类化合物发生了反应。
1,4-萘醌与
4-羟基-3,4-二苯基环戊-2-烯酮反应生成 2,3-二苯基
蒽醌,而苯醌与相同的
环戊二烯酮前体反应生成 6,7
-二苯基-1,4-萘醌和 2,3,6,7-四苯基
蒽醌的混合物。同样,通过
1,4-萘醌与适当的
4-羟基-3,4-二芳基环戊-2-烯酮的反应,也以中等产率制备出了其他一些 2,3-二芳基
蒽醌。这种方法似乎普遍适用于利用廉价的起始材料合成 2-位和 3-位取代的
蒽醌衍
生物。