The Structure of the Lichen Depsidones Fulgidin and Isofulgidin

Abstract

The depsidone isofulgidin (1) (2,4,7-trichloro-3-hydroxy-8-methoxy-1,6-dimethyl-11H-dibenzo-[ b,el [1,4]dioxepin-11-one), has been isolated from the lichen Rinodina dissa together with atranorin and diploicin (3). lsofulgidin (1) has also been detected in the lichens Hafellia parastata and Fulgensia canariensis. The structure of the isomeric lichen depsidone fulgidin has been established as 2,4,9-trichloro-3-hydroxy-8-methoxy-1,6-dimethyl-11H-dibenzo[ b,e ][1,4]dioxepin-11-one (4) by unambiguous synthesis.