Michael addition approach for the synthesis of novel spiro compounds and 2-substituted malonic acid derivatives from Meldrum’s acid

Novel routes for the synthesis of spiro derivatives of Meldrum’s acid and 2-substituted malonic acid derivatives have been developed. Meldrum’s acid was monoalkylated using a Michael addition reaction. Mono-Michael adducts were then alkylated using substituted haloalkanes, which on condensation gave spiro derivatives of Meldrum’s acid. Bis Michael addition of Meldrum’s acid with 1,5-diaryl-1,4-pentadien-3-one gave directly a spiro derivative of Meldrum’s acid. These compounds and bis alkylated Meldrum’s acid derivatives, on acidic methanolysis gave 2-substituted malonic acids.