It features a copper-catalyzed reductive aldolization followed by a lactonization.
Zhengning Li, Chongnian Wang, Zengchang Li 2015, 'Copper-catalyzed cascade reactions of α,β-unsaturated esters with keto esters', Beilstein Journal of Organic Chemistryhttps://doi.org/10.3762/bjoc.11.23. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
This strategy relies on acetylation, aldolization, cyclization and hydrolysis reactions, respectively.
Ze-Xi Dong, Nian-Guang Li, Peng-Xuan Zhang, Ting Gu, Wen-Yu Wu, Zhi-Hao Shi 2016, 'An Efficient Chemical Synthesis of Scutellarein: An in Vivo Metabolite of Scutellarin',Moleculeshttp://www.mdpi.com/1420-3049/21/3/263. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)