A New Access to 1,8-Dioxooctahydroxanthenes Using Yttrium(III) Nitrate Hexahydrate and Tin(II) Chloride Dihydrate as Effective and Reusable Catalysts
作者:B. Karami、K. Eskandari、Z. Zare、S. Gholipour
DOI:10.1007/s10593-014-1423-5
日期:2014.3
environmentally adapted synthesis of xanthene derivatives by condensation of a wide range of aryl aldehydes and cyclohexane-1,3-diones in the presence of catalytic amounts of yttrium(III) nitrate hexahydrate and tin(II) chloride dihydrate is demonstrated.
safer procedure from anhydrous sodium tungstate with chlorosulfonic acid (1:2 mole) in n-hexane (Scheme 1).16–18 We now describe the use of TSA for the synthesis of 1,8-dioxoöctahydroxanthenes 3 by condensation of 1,3-cyclohexanediones 1 with aromatic aldehydes 2 undersolvent-freeconditions (Scheme 2). The structures of the products were deduced from their IR, NMR spectroscopic data and their melting