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Updated: Sep 23, 2026

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
Published on: August 22, 2018
Structure and absolute configuration of a high affinity 5-HT3 receptor antagonist,
H L Ammon1, R D Youssefyeh, J E Airey
1Department of Chemistry and Biochemistry, University of Maryland, College Park 20742.
Abstract:
The absolute configuration was established as (S,S,S) by the R-factor test and by careful measurement of 197 enantiomorph-sensitive Friedel pairs of reflections. The determination also confirms the absolute stereochemistry of (-)-3-aminoquinuclidine, a compound used in the preparation of the title material. The cyclohexane/tetrahydrofuran ring fusion is cis. The quinuclidine moiety has almost perfect threefold symmetry; the front and rear halves are twisted about this axis by 15 degrees. Quinuclidine-N--H ... Cl- and amide-N--H ... Cl- hydrogen bonds link screw-dyad-related molecules along the b axis.
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