A single-step synthesis of ayapin, limnmettin, scoparone, leptodactylone, fraxinol, isoscopoletin, 5,6,7- trimethoxy cournarin and 7-methoxy-8-hydroxy coumarin

Abstract

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