Total Synthesis of Alternariol

Abstract

Total synthesis of alternariol, a toxic secondary metabolite of various Alternaria fungi, was achieved in seven steps starting with orcinol and 3,5-dimethoxybromobenzene. The longest linear sequence consists of six steps. Key reaction is a palladium-catalyzed Suzuki-type coupling of an orcinol-derived boronic acid with a brominated resorcylic aldehyde. The final demethylation furnished alternariol in 73% yield containing a smaller fraction of alternariol 9-methyl ether (approximately 20%).