The role of free solvent system reaction in environmentally safe and economical technologies, mainly in chemical manufacturing processes and green chemistry is inevitable. Furthermore, the key role of free solvent as condition in the synthesis of heterocycles and other organic compounds is well-known. After completion of reaction, they can easily separate from reaction mixture. Furthermore,considering green chemistry aspects, due to reducing organic solvent in synthesis process. A one pot-condensation of dimedone and apprioriate aromatic aldehyde, has susccesfuly used to free solvent synthesis one of octahydroxanthene analogue using H2SO4 catalyst. The idea of this research is to make the catalyst acts as Bronsted acid for enolization on benzaldehyde so it is easier to form Biginelli like condensation. The synthesis which was carried out under free solvent condition for 2 hours resulting good yield. Octahydroxanthene structure was studied based on spectroscopic data including UV-Vis, FTIR and 1H-NMR.