A single-step synthesis of ayapin, limmettin, scoparone, leptodactylone, fraxinol, isoscopoletin, 5,6,7-trimethoxy coumarin and 7-methoxy-8-hy-droxy coumarin

Abstract

A single-step synthesis of eight natural coumarins, namely, ayapin, limmetin, scoparone, leptodactylone, fraxinol, isoscopoletin, 5,6,7-trimethoxy coumarin and 7-methoxy-8-hydroxy coumarin is hang reported. The method involves the transfer of C-3 umt of cinnamic acids on to appropriate phenols in the presence of polyphosphorice acid (PPA) to obtain the corresponding coumanns. The ease with which the reaction occurs, the moderately good yields and the ready availability of starring materials are hallmarks of this reaction. The scope of the reaction has heen discussed in the present paper.