X-ray structural investigation of 1,3,6-trichloro-3,6-dimethylcycloheptanecarbonitrile and 2,5-dimethyl-2,5-dichlorohexane - the products of reaction of 2,5-dimethyl-1,5- hexadiene with trichloroacetonitrile
A. A. Karapetyan, R. A. Tamazyan, A. R. Mikaelyan, A. M. Grigoryan, A. S. Vardanyan, L. Z. Nikogosyan
Keywords: regio- and stereospecific intramolecular cyclization, cycloheptanecarbonitrile
Pages: 997-1000
Abstract
Addition of trichloroacetonitrile to 2,5-dimethyl-1,5-hexadiene in presence of cuprous amine complexes has been studied. Single crystal X-ray diffraction unambiguously proves that the main product is a racemic mixture of the cyclic symmetric nitrile - (1r,3R,6S)- and (1r,3S,6R)-1,3,6-trichloro-3,6-dimethylcycloheptanecarbonitrile. Established relative configuration of the product confirms the ring closure mechanism suggested before. Also, a side product - 2,5-dimethyl-2,5-dichlorohexane has been isolated (the product of hydrochlorination of the starting alkadiene). Low-temperature (190 K) structural examination of this centrosymmetrical molecule indicates that the unit cell comprises one molecule.
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