Depsidone synthesis. Part 11. Synthesis of some fungal depsidones related to nidulin

Abstract

The synthesis of 3-hydroxy-8-methoxy-1,9-dimethyl-6-(s-butyl)dibenzo[b,e][1,4]dioxepin-11-one (tridechlorodihydronidulin)(34), a derivative of the fungal depsidone nidulin (1), and of 3,8-dihydroxy-1,9-dimethyl-6-(s-butyl)dibenzo[b,e][1,4]dioxepin-11-one (tridechlorodihydro-O-nornidulin)(39), a derivative of the fungal depsidone tridechloro-O-nornidulin (4), by oxidative coupling of 5-bromo-2,2′,4′-trihydroxy-4-methoxy-3,6′-di-methyl-6-(s-butyl)benzophenone (30) is described.