The annulation method based on 2H-cyclohepta [b] furan-2-ones was applied for the synthesis of 2-alkylazulenes; 2-R-azulene (R= Et, i-Pr, n-Pr, i-Bu). Tropolone p- toluenesulfonate was used as a starting compound. By the two step synthesis, 1-carboxylic- 3-cyanoazulene derivatives were obtained. Treatment of 1-carboxylic-3-cyanoazulene derivatives with aq H2SO4 resulted in decarboxylation and elimination of cyano group to ...