Pure Appl. Chem., 2003, Vol. 75, No. 4, pp. 421-425
http://dx.doi.org/10.1351/pac200375040421
Synthesis of coumarins by ring-closing metathesis
Abstract:
Investigations into olefin ring-closing metathesis (RCM) have led to a general method for the synthesis of coumarins. Catalysts with higher activity, such as the second-generation ruthenium catalyst, promote the intramolecular reaction between two-electron deficient olefins. This method allows for convenient access to a variety of coumarins substituted at both the 3- and 4-positions, as well as a tetrasubstituted example.