Ethylenediammonium diacetate readily catalyzes the Knoevenagel-type condensation between 1,3-dicarbonyl substrates and α,β-unsaturated aldehydes at room temperature under solvent-free conditions. This rapid, efficient, and convenient one-pot approach to the synthesis of 2H-pyrans stands as a significant advance over previously reported protocols. This environmentally friendly methodology has been successfully applied to the synthesis of biologically active natural products of interest zanthosimuline, N-methylflindersine, and ferprenin.Fil: Riveira, Martín Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; ArgentinaFil: Mischne, Mirta Paulina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; Argentina