Synthesis of the Altertoxin I Framework

Abstract Routes to the framework of perylenequinone‐derived mycotoxins of the biphenyl type are described. 1,2,11,12‐Tetrahydroperylenequinone is most suitably prepared in seven steps starting with 3‐hydroxyacetophenone. Key steps are an Ullmann coupling, pinacol‐type cyclization, bromination, enolate reaction, and intramolecular Friedel‐Crafts cyclization. A second approach starting with 1,5‐dihydroxynaphthalene yields the respective decarbonylated core. Key steps of this 5‐step sequence are again an Ullmann coupling and a McMurry olefination. The cleavage of the preferentially utilized hexyl protecting group could be achieved with boron bromide.