cis,cis,cis-tetramethyl 1,2,4,5-cyclohexanetetracarboxylate

The title compound, C(14)H(20)O(8), was synthesized from the hydrogenation of tetramethyl 1,4-cyclohexadiene-1,2,4, 5-tetracarboxylate with a catalytic amount of palladium/carbon. All four carbonyl moieties of the methyl ester groups are on the same face of the chair-conformed ring. The substantial ring distortion associated with the 1,3-diaxial methoxycarbonyl substituents is reflected in the large difference between bond angles as well as torsion angles, respectively, that in undistorted cyclohexanes would be approximately the same.