Efficient and Green Synthesis of Novel 2-Amino-3-cyano-6-(phosphonoethyl)-4H-pyrans

Herein we report a convenient and green synthesis of a new class of phosphonopyrans—2-amino-3-cyano-6-phosphonoethyl-4H-pyrans—through the K₂CO₃-catalyzed reaction of malononitrile with γ-keto-δ-alkenylphosphine oxides. The reaction proceeds under operationally simple and mild conditions, employs a low-cost and an environmentally benign catalyst and ethanol as a green solvent.