An efficient route to dipyrrinones: Synthesis of xanthobilirubic acid methyl ester

Article abstract of DOI:10.1055/s-1990-27094

Structurally interesting and complicated dipyrrinones, such as xanthobilirubic acid methyl ester (9), can be synthesized on a large scale from simple, inexpensive starting materials like ethyl acetoacetate, 2,4-pentanedione (1) and ethyl acrylate in 8 steps with an average yield of 80% at each step and an overall 17% yield.