Bildung, Kristallstruktur und absolute Konfiguration von (−)-N-(Chloromethyl)galanthaminium-chlorid
✍ Scribed by Rudolf Matusch; Mirko Kreh; Ulrich Müller
- Publisher
- John Wiley and Sons
- Year
- 1994
- Tongue
- German
- Weight
- 305 KB
- Volume
- 77
- Category
- Article
- ISSN
- 0018-019X
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✦ Synopsis
Formation, X‐Ray Crystal Structure, and Absolute Configuration of (−)‐N‐(Chloromethyl)galanthaminium Chloride
The acetylcholinesterase inhibitor galanthamine (1), main alkaloid of several Narcissus species, readily forms a quaternary ammonium salt by reaction with the solvent CH~2~Cl~2~. The structure and absolute configuration of (−)‐N‐(chloromethyl)galanthaminium chloride (2) were determined by X‐ray diffraction (R = 0.075 for 2775 observed independent reflexions) and NMR spectroscopy. The tetragonal crystals (space group __P__4~3~) contain two crystallographically independent cations which do not differ significantly from one another. The CH~2~Cl group is attached to the quaternary N‐atom in stereospecific (R)‐configuration. In the crystal, the configurational position of the Me group at the N‐atom of 2 differs from that of the crystalline free base 1. Hydrogen bonding is observed from the OH group at C(3) of 2 to the Cl^−^ anion or to the Cl‐atom of an adjacent cation.