Rel-(1R,2S,4S)-Cyclohexane-1,2,4-tricarboxylic Acid

This compound is typically isolated as a white crystalline powder. Its molecular formula is C9H12O6, corresponding to a molecular weight of 216.19. The melting point generally exceeds 200°C, often with decomposition observed upon prolonged heating above this range. It is soluble in polar organic solvents such as methanol, ethanol, and dimethyl sulfoxide, moderately soluble in water due to the multiple carboxylic acid groups, and practically insoluble in nonpolar solvents like dichloromethane and hexane. The molecule features a cyclohexane ring bearing three carboxylic acid substituents at the 1, 2, and 4 positions, with defined relative stereochemistry. The carboxylic acids are susceptible to deprotonation, esterification, and amide formation. Storage in tightly sealed containers protected from light and moisture at ambient temperature is generally adequate, though desiccated conditions are recommended for prolonged periods. Contact with strong oxidizing agents and strong bases should be avoided.

rel-(1R,2S,4S)-Cyclohexane-1,2,4-tricarboxylic acid is a stereochemically defined cyclic tricarboxylic acid in which three carboxyl groups are attached to a saturated six-membered ring. The relative configuration specified by (1R,2S,4S) indicates a specific spatial arrangement of these substituents around the cyclohexane core, which exists predominantly in a chair conformation with the carboxyl groups occupying defined equatorial and axial positions to minimize steric strain. This rigid, chiral framework provides a well-defined three-dimensional scaffold for presenting carboxylic acid functionalities at precise orientations. The molecule combines the coordinative versatility of multiple carboxylate groups with the conformational rigidity of the cyclohexane ring, enabling selective interactions with metal ions, proteins, or other binding partners. Its defined stereochemistry and multiple coordination sites make it a valuable building block in coordination chemistry, supramolecular chemistry, and the design of biologically active molecules.

Building Block for Metal-Organic Frameworks
This tricarboxylic acid serves as a rigid, multitopic linker for constructing metal-organic frameworks with well-defined pore architectures. The three carboxylate groups can coordinate to metal ions or clusters, forming extended three-dimensional networks with high surface areas and permanent porosity. The defined stereochemistry and rigid cyclohexane core impart structural predictability, enabling the design of frameworks with tailored pore sizes and chemical environments for applications in gas storage, separation, and heterogeneous catalysis.

Chiral Ligand in Asymmetric Catalysis
The defined stereocenters and multiple coordinating sites make this compound a valuable precursor for designing chiral ligands used in enantioselective transformations. The carboxyl groups can be derivatized to introduce phosphine, amine, or other donor functionalities while maintaining the rigid chiral backbone. Metal complexes derived from such ligands are investigated for their ability to induce high enantioselectivity in hydrogenation, epoxidation, and cross-coupling reactions.

Intermediate for Pharmaceutical Synthesis
In medicinal chemistry, this tricarboxylic acid serves as a starting material for preparing conformationally constrained analogs of bioactive molecules. The rigid cyclohexane core can replace flexible chains in drug candidates, potentially improving target selectivity and metabolic stability through reduced conformational entropy. The carboxyl groups provide handles for amide coupling with amine-containing pharmacophores or for esterification to modulate pharmacokinetic properties.

Supramolecular Chemistry and Crystal Engineering
The multiple hydrogen-bonding sites and defined geometry of this compound make it valuable for constructing supramolecular assemblies through non-covalent interactions. It can form hydrogen-bonded networks with complementary partners such as amines, pyridines, or other carboxylic acids, yielding co-crystals and molecular complexes with predictable architectures. These studies inform the design of functional materials and pharmaceutical co-crystals with improved physicochemical properties.