%0 Journal Article %T Efficient Solvent Free Synthesis of 12-Aryl-8,9,10,12-tetrahydrobenzo[a]-xanthen-11-ones and 3H-Spiro[isobenzofuran-1,9'-xanthen]-3-one Derivatives Using Cobalt Hydrogensulfate as a Green, Heterogeneous and Reusable Catalyst %A Eshghi, Hossein %A Eftekhar, Melika %A Rahimizadeh, Mohammad %A Hasanpour Mansour, Maede %A Bakavoli, Mehdi %J Organic Chemistry Research %@ 2383-242X %D 2016