3-Ethoxycarbonyl-and 3-acetyl-2H-cyclohepta [b] furan-2-ones react easily with malonitrile. cyanoacetamide, ethyl cyanoacetate and diethyl malonate, in the presence of sodium ethoxide or t-butyl-amine, giving the corresponding 1, 2, 3-trisubstituted azulene derivatives, respectively. The structures of these azulene derivatives are determined on the basis of chemical evidence, and spectral data. Considering the structural correlation between the ...