An Efficient Synthesis of <i>p</i><i>eri</i>-Hydroxy Aromatic Compounds via a Strong-Base-Induced [4+2] Cycloaddition of Homophthalic Anhydrides with Enolizable Enones
作者:Kiyosei Iio、Namakkal G. Ramesh、Akiko Okajima、Kazuhiro Higuchi、Hiromichi Fujioka、Shuji Akai、Yasuyuki Kita
DOI:10.1021/jo990649q
日期:2000.1.1
An efficient synthesis of peri-hydroxy aromatic compounds has been accomplished via a strong-base-induced [4+2] cycloaddition of homophthalic anhydrides with alpha-sulfinyl-substituted derivatives of enolizable enones. The unsubstituted enones did not undergo an efficient [4+2] cycloaddition reaction with homophthalic anhydrides, presumably due to their enolization under the basic reaction conditions
高羟基芳族化合物的有效合成已通过高碱诱导的高邻苯二甲酸酐与可烯醇化的烯酮的α-亚磺酰基取代的衍生物的[4 + 2]环加成反应完成。未取代的烯酮与高邻苯二甲酸酐未进行有效的[4 + 2]环加成反应,可能是由于它们在碱性反应条件下被烯醇化。亚磺酰基不仅促进环加成反应,而且在反应条件下进行原位消除,从而一步得到环羟基芳族化合物。描述了该方法在合成抗肿瘤抗生素腓特烈霉素A的关键中间体中的应用。还讨论了各种2-取代的环戊烯酮的PM3计算以及环加成的机理。