Department of Chemistry, Tehran North Branch, Islamic Azad University, Tehran, P.O. Box 191367-4711 Tehran, I.R. IRAN
Tetrahydrobenzo[b]pyran derivatives 1 were utilized for the synthesis of several new pyrano[2,3-d]pyrimidine derivatives 2. Compound 2 was obtained in the presence of Ac2O/H2SO4 (as a catalyst) and was confirmed by spectroscopic data such as IR, 1H NMR and 13C NMR. Ab initio calculation was carried out to study geometric optimization, thermodynamic parameters, aromaticity and dynamic process of conformational analysis for compound 2.