- SYNTHESIS OF SUBSTITUTED 4-(METHOXYPHENYL)-3,4-DIHYDROCOUMARINS
-
In polyphosphoric acid (PPA), 2- and 4-methoxycinnamic acids react with various dimethylphenols to give 4-phenyl-3,4-dihydrocoumarins by direct cycloaddition, whereas 3-methoxycinnamic acid, in the same conditions, also gives a flavanone formed by Fries rearrangement from a hydroxychalcone.These results are discussed in terms of electronic effects due to the methoxy substituents on the cinnamic acid.
- Chenault, Jacques,Dupin, Jean-Francois E.
-
p. 437 - 443
(2007/10/02)
-