The reaction of enolates of 1,3-dicarbonyl compounds (1) with 3,4-dibromo-2-butanone (2) afforded hydrofuran derivatives (4) or (5) in the presence of DBU in THF and the reaction was applied to the one-pot synthesis of antitumor naphthofuran natural products (29).
Domino Michael–O-alkylation reaction: one-pot synthesis of 2,4-diacylhydrofuran derivatives and its application to antitumor naphthofuran synthesis
The reaction of enolates of 1,3-dicarbonyl compounds with α-halo-α,β-unsaturated carbonyl compounds affords 2,4-diacyldihydrofuran derivatives in the presence of DBU in THF. Chemical manganese dioxide oxidation of the hydrofurans leads to 2,4-diacylfuran derivatives. Application of the protocol enables short-step syntheses of antitumor naphthofuran natural products.