Synthesis of Phenylsubstituted 2H,5H-Pyrano[ 4,3-b] pyran-5-ones and Related Heterocycles via a Domino Knoevenagel Condensation/ 6π-Electron Electrocyclization of 4-Hydroxy-6-phenyl-2H-pyran-2-one with Cyclic and Acyclic α, β-Unsaturated Aldehydes under Different Conditions Synthesis and Crystal Structure of the High-pressure Iron Borate β-FeB2O4 Synthesis and Crystal Structure of the High-pressure Iron Borate β-FeB2O4 Synthesis and Crystal Structure of the High-pressure Iron Borate β-FeB2O4 Synthesis and

Abstract

A range of new 7-phenyl-2H,5H-pyrano[4,3-b]pyran-5-ones and related tricyclic heterocycles was prepared in a single step by means of a domino Knoevenagel condensation/6π-electron electrocyclization under different reaction conditions, including thermal and microwave conditions. The influence of several ionic liquids as solvents was also studied