Yb(OTf)<sub>3</sub>-Catalyzed Reactions of 5-Alkylidene Meldrum's Acids with Phenols: One-Pot Assembly of 3,4-Dihydrocoumarins, 4-Chromanones, Coumarins, and Chromones
作者:Eric Fillion、Aaron M. Dumas、Bryan A. Kuropatwa、Neil R. Malhotra、Tamsyn C. Sitler
DOI:10.1021/jo052000t
日期:2006.1.1
Yb(OTf)3-catalyzed annulation reactions of phenols with 5-alkylidene Meldrum's acids enabled the synthesis of structurally diverse heterocycles in high isolated yields. A series of 4-substituted 3,4-dihydrocoumarins, 2,2-disubstituted 4-chromanones, coumarins, and 2-substituted chromones were readily and efficiently assembled, including the naturallyoccurringcoumarins citropten, scoparone, and ayapin