OPTICAL RESOLUTION OF TRANS-BICYCLO[2.2.1]HEPTANE-2,3-DIAMINE - CHIRAL RECOGNITION IN THE CRYSTAL OF ITS COMPLEX WITH (2R,3R)-O,O'-DIBENZOYLTARTARIC ACID

The synthesis of trans-bicyclo[2.2.1]heptane-2,3-diamine (6c), its optical resolution via formation of its complex with (2R,3R)-O,O'-dibenzoyltartaric acid (-BTA). and the crystal structure determination of this complex by X-ray diffraction techniques are reported. The absolute configuration of 6c in the complex has been determined to be (S,S)-6c from the endowed chirality of -BTA, thus optical resolution of 6c is achieved. Crystal data for the (S,S)-6c (-BTA) complex is reported: C25H28N2O8.2H(2)O, M = 520.54, monoclinic P2(1), a = 9.150(1), b = 8.581(1), c = 17.036(1) Angstrom, beta = 103.30(1)degrees, V = 1301(2) Angstrom(3), Z = 2, R = 0.037. The crystal of the molecular complex is found to have a multilamellar structure partitioned by thin hydrogen bonded sheets containing complex ammonium-carboxylate-water hydrogen bonds. Attached on both sides of the sheet, monolayer templates with benzoyl groups of -BTA and bicycloheptane fragments of 6c stack with the next templates to form hydrophobic bilayers. In the monolayer template, a cavity is formed surrounded by two pairs of two benzoyl groups distinguished from each other by their orientations toward the hydrogen bond sheet. The cavity provides a final site for the chiral recognition of 6c. The (S,S)-enantiomer of 6c is probably distinguished from the (R,R)-enantiomer by the favourable orientation of bicycloheptane skeleton in the cavity.