ONE-POT FORMATION OF FUNCTIONALISED 2-PIPERIDINONES FROM ARYLIDENECYANOACETATES AND METHANOLIC AMMONIA VIA TANDEM REACTIONS

摘要

Aryl aldehydes react with ethyl cyanoacetate in methanolic ammonium acetate to expeditiously furnish,besides high yields of arylidenecyanoacetates,4,6-diaryl-3,5-dicyano-5-ethoxycarbonyl-2-piperidinones in low yields.But preformed arylidenecyanoacetates react with methanolic ammonia to furnish the same functionalised 2-piperidinones in much better yields.The actual stereostructure of one of the products was determined by single crystal X-ray diffraction analysis,and novel tandem reactions occurring in one pot are proposed for the formation of the products.