27862-85-7Relevant articles and documents
Optical Resolution of trans-Bicycloheptane-2,3-diamine: Chiral Recognition in the Crystal of its Complex with (2R,3R)-O,O'-Dibenzoyltartaric Acid
Hatano, Keiichiro,Takeda, Tadahiro,Saito, Reiko
, p. 579 - 584 (2007/10/02)
The synthesis of trans-bicycloheptane-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*2H2O, M = 520.54, monoclinic P21, a = 9.150(1), b = 8.581(1), c = 17.036(1) Angstroem, β = 103,30(1) deg, V = 1301(2) Angstroem3, 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.
Chiral rhodium-diphosphine catalyst capable of catalytic reduction of a tetramisole precursor to give a significant excess of the desired S-(-)isomer, levamisole
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, (2008/06/13)
A soluble, chiral, rhodium-containing catalyst which permits the catalytic reduction of prochiral 3-acyl-1-(2-alkoxyethyl)-4-phenyl-2-imidazolinones to chiral 3-acylimidazolidinones with a substantial excess of the desired S optical isomer. The 3-acylimidazolidinones may in turn be substantially converted to levamisole, and S isomer of tetramisole. The resolution of tetramisole to remove the R isomer is thus avoided.
