In water, Green and Efficient Multicomponent Synthesis of 4H-Pyran Derivatives catalyzed by LiOH·H 2 O under Ultrasound Irradiation

Abstract

This research work introduce a straightforward and efficient method for synthesizing 4H-pyrans via a multi-component cyclocondensation reaction involving aromatic aldehydes, malononitrile, and ethyl acetoacetate. This environmentally friendly approach utilizes ultrasound and water as the reaction medium, enabling the production of 4H-pyrans with good yields at room temperature. Notably, commercially available LiOH·H2O serves as a dual-activated catalyst, facilitating the formation of benzylidene intermediates and serving as a mild base for 4H-pyran production. The simplicity of the operational procedure, short reaction times, cleanliness, low cost and ready availability of LiOH·H2O, high efficiency, and excellent yields collectively render this novel approach highly appealing for 4H-pyran synthesis.