Molecular structures and conformations of three 3-azabicyclononanes
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Updated: Oct 15, 2026

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
Published on: August 22, 2018
Kumaran1, Ponnuswamy, Shanmugam
1Department of Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai 600 025, India.
Abstract:
The structure, conformation, molecular geometry and the mode of packing of 7-tert-butyl-N-methyl-2,4-diphenyl-3-azabicyclo[3.3.1]nonane (C(25)H(33)N; MTABN), N-acetyl-2,4-diphenyl-3-azabicyclo[3.3.1]nonane (C(22)H(25)NO; AABN) and N-methyl-2,4-bis(2-methylphenyl)-3-azabicyclo[3.3.1]nonan-9-ol (C(23)H(29)NO; MHABN) are presented. The compounds MTABN and MHABN crystallize in monoclinic space groups, whereas AABN is orthorhombic. In each of the three structures, the bicyclic ring system adopts a chair-chair conformation and the phenyl rings are in equatorial orientation with respect to the piperidine ring. In AABN, apart from the van der Waals forces, weak intermolecular C-H.O type interactions are involved in the packing.
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