Cycloaddition to 1, 3-Dialkoxycarbonylallenes : One-Step Synthesis of Heterocyclic Compounds Containing a Dialkyl Glutaconate Structure

Abstract

A novel synthesis of alkyl 2-alkoxycarbonyl-3-pyridineacetates (2), alkyl 3-alkoxycarbonyl-4-pyrazoleacetate (5), and alkyl 5-alkoxycarbonyl-4-(1, 2, 3-triazole) acetate (6) is described. Diels-Alder reaction of 1, 3-dialkoxycarbonylallenes (3) with 1-azadiene systems (4) gave 2, and 1, 3-dipolar cycloaddition of 3 to diazoalkanes and trimethylsilylazide gave 5 and 6, respectively. The structures of the cycloadducts and the regiochemistry of the cycloadditions are discussed.