Biomimetic Syntheses of Amorfrutin C and C‐5 Substituted Amorfrutin Analogues

Abstract

AbstractAmorfrutin C, a C‐5 prenyl amorfrutin, its allyl analog and an amorfrutin C‐5 aldehyde have been synthesized using a biomimetic strategy from non‐aromatic precursors. In this approach, a dioxinone derived β,δ‐diketo ester underwent a decarboxylative Pd(0) catalyzed prenyl migration to give a β,δ‐diketo dioxinone, which readily aromatized giving the amorfrutin core. The introduction of prenyl and allyl moieties at the C‐5 position of the scaffold was accomplished using a Claisen rearrangement. Alternatively, iodination, lithium‐iodine exchange and trapping with DMF gave the amorfrutin aldehyde and an amorfrutin alcohol when excess n‐BuLi was used.