AUTHOR=Wei Kai , Sun Yucui , Xu Yiren , Hu Wen , Ma Ying , Lu Yi , Chen Wen , Zhang Hongbin 

TITLE=Total synthesis of justicidin B, justicidin E, and taiwanin C: A general and flexible approach toward the synthesis of natural arylnaphthalene lactone lignans

JOURNAL=Frontiers in Chemistry

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2022.1103554

DOI=10.3389/fchem.2022.1103554

ISSN=2296-2646

ABSTRACT=<p>Lignans are widely present in traditional medicinal plants. Many natural arylnaphthalene lactone lignans (NALLs) isolated from the genera <italic>Justicia</italic>, <italic>Haplophyllum</italic>, and <italic>Phyllanthus</italic> possess interesting biological activities. Herein, we report a general strategy for the total synthesis of this kind of lignans. Features of this new approach are an aryl–alkyl Suzuki cross-coupling to introduce the dioxinone unit, a cation-induced cyclization to construct the aryl dihydronaphthalene, and base-mediated oxidative aromatization to furnish the arylnaphthalene core. By incorporating these key transformations, the total syntheses of justicidins B and E and taiwanin C covered type I and type II NALLs were accomplished.</p>