A versatile synthesis of fumaquinone.

Fumaquinone, a novel prenylated naphthoquinone antibiotic, was synthetized from ethyl acetoacetate in three steps (58% overall yield). The key step of the synthesis is the construction of the naphthoquinone skeleton by a regioselective Diels-Alder reaction between a 2-alkyl 1,3-bis(trimethylsilyloxy)-1,3-diene derivative and a bromoquinone. This short and versatile approach confirms the structure of fumaquinone and allows the synthesis of derivatives at the C-6 position.