α-Bromo-α,β-unsaturatedesters and α-bromobutenolides reacted with sodium salts of methyl malonamates to afford cyclopropanes, α-methoxycarbonyllactams and 5-amino-4-methoxycarbonyl-2,3-dihydrofurans. The last compounds could be easily converted into α-methoxycarbonyl-γ-lactones. The ratio of these compounds formed is influenced by the structures of both malonamates and unsaturated compounds, especially
A new method for the stereoselective synthesis of (±)-avenaciolide and its analogues via methoxycarbonyl- or anisyloxycarbonyldi-γ-lactones, which could be easily prepared by the reaction of γ-substituted α-bromobutenolides with sodium salt of methyl or anisyl malonamate in good yields, was described.