The Identification and Synthesis of Further Lichen β-Orcinol para-Depsides

Abstract

The new lichen depsides, methyl 5-chloronorobtusatate (4) and 4-O-demethyldiffractaic acid (5), have been detected in an Erioderma sp. And Xanthoparmelia duplicata Hale respectively, and the structures confirmed by total synthesis. In addition, the lichen depsides, 2'-O- methylatranorin (1), 2-O-methylsquamatic acid (2) and elatinic acid (3), have been prepared by unambiguous synthesis for the first time.