Condensation of Diethyl Acetonedicarboxylate. II

Abstract

Selfcondensation of diethyl acetonedicarboxylate (DADC) gave two types of products and the six kinds of the products were formed by using various catalysts. In order to elucidate the reaction mechanism of DADC for giving these products, the roles of catalysts were investigated. The formation mechanism of the orsellinic acid derivatives (1, 2, 3, and 4) was proposed, and the magnesium-DADC chelated complex (B) was recommended for the intermediate of these products. Furthermore, the mechanisms giving the coumarin derivatives (5 and 6) were discussed.