9-(2,3-Dichloro­phen­yl)-4a-hydr­oxy-3,3,6,6-tetra­methyl-4,4a,5,6,9,9a-hexa­hydro-3H-xanthene-1,8(2H,7H)-dione

Mol­ecules of the title compound, C23H26Cl2O4, are linked by hydrogen bonds between the hydroxyl O atom and the carbonyl O atom of a neighboring mol­ecule. The central hydropyran and fused cyclohexanone rings adopt half-chair conformations, while the fused hydroxycyclohexanone ring adopts a chair conformation

A highly efficient green synthesis of 1, 8-dioxo-octahydroxanthenes

SmCl3 (20 mol%) has been used as an efficient catalyst for reaction between aromatic aldehydes and 5,5-dimethyl-1,3-cyclohexanedione at 120°C to give 1,8-dioxo-octahydroxanthene derivatives in high yield. The same reaction in water, at room temperature gave only the open chain analogue of 1,8-dioxo-octahydroxanthene. Use of eco-friendly green Lewis acid, readily available catalyst and easy isolation of the product makes this a convenient method for the synthesis of either of the products

Benzylation of hydroxy groups with tertiary amine as a base

The benzylation of hydroxy groups in the presence of tertiary amines is described. A mixture of an alcohol and a benzyl halide afforded the corresponding benzyl ether in good to excellent yields in the presence of diisopropylethylamine. The importance of solventless conditions was observed. The reaction showed high tolerance to many functional groups including benzoate, even at a reaction temperature of 150 °C. Sodium iodide was found to be an efficient catalyst to accelerate the reaction