In this work we report the reaction between dialkyl acetylenedicarboxylates and enolic systems such as 5,5-dimethyl-1,3-cyclohexanedione, 1,3-cyclohexanedione, 4-hydroxycoumarin or 4-hydroxy-6-methylpyran-1-one in the presence of isoquinoline, which leads to new coumarin and pyranopyran derivatives.
acetylenedicarboxylic esters; isoquinoline; pyranopyran derivatives; coumarin derivatives