Facile Installation of a Hydroxyalkyl Group into Hydroxyanthraquinones and Aminoanthraquinones through the Modified Marschalk Reaction

1,4-Dihydroxyanthraquinones are widely featured in numerous natural products and drugs. It is important to be able to functionalize the 1,4-dihydroxyanthraquinone skeleton through a simple yet efficient transformation, which could be potentially useful for the drug discovery process. We describe herein a simple and efficient method to derivatize 1,4-dihydroxyanthraquinone by using a modified Marschalk reaction. This method provides a clear advantage over traditional approaches, which often require the protection and deprotection of the OH groups. We also demonstrate the applicability of this reaction to other hydroxyanthraquinones and aminoanthraquinones.