Synthesis of 4-Hydroxy-1H-pyrrole-2,3-dicarboxylic Acid Derivatives: Unusual Coupling of Acetylenic Esters and α-Amino Acids in the Presence of Cyclohexyl Isocyanide or N,N′-Dicyclohexylcarbodiimide

Abstract

A facile and direct synthetic entry to 4-hydroxy-1H-pyrrole-2,3-dicarboxylic acid derivatives is reported. It is based on the unusual ring annulation of acetylenic esters and α-amino acids with isocyanide or carbodiimide under neutral conditions in a one-step procedure.