Tetrahedron Letters

Bi (OTf) 3-catalyzed solvent-free synthesis of pyrano [3, 2-c] coumarins through a tandem addition/annulation reaction between chalcones and 4-hydroxycoumarins

M Gohain, JH van Tonder, BCB Bezuidenhoudt

Index: Gohain, Mukut; Van Tonder, Johannes H.; Bezuidenhoudt, Barend C.B. Tetrahedron Letters, 2013 , vol. 54, # 29 p. 3773 - 3776

Full Text: HTML

Citation Number: 7

Abstract

A Bi (OTf) 3-catalyzed tandem addition/annulation reaction is described in order to synthesize pyrano [3, 2-c] coumarins under solvent-free conditions. Substituted/ unsubstituted chalcones were conveniently condensed with various 4-hydroxycoumarins by means of this environmentally benign method which produces water as the only side product.