B(C₆F₅)₃ catalyzed synthesis of dihydropyrano[3,2-b]chromenediones under solvent-free conditions

Abstract

A simple, efficient, solventless, and one step, B(C₆F₅)₃ catalyzed, synthesis of dihydropyrano[3,2-b]chromenediones from dimedone, aldehyde and kojic acid is described. This protocol proceeds smoothly, accommodates aromatic as well as heteroaromatic aldehydes and gives dihydropyrano[3,2-b]chromenediones in excellent yield.

GRAPHICAL ABSTRACT

Keywords:

• Aldehyde
• chromenedione
• dimedone
• kojic acid
• tris(pentafluorophenyl)borane

Acknowledgments

The authors are grateful to the Department of Postgraduate Studies and Research in Chemistry, Dnyanopasak College, Parbhani and Shri Chhatrapati Shivaji College, Omerga, India, for providing laboratory facilities and Indian Institute of Chemical Technology, Hyderabad for spectral analysis.