Crystal Structure of Akuammigine Picrate Hydrate

✍ Scribed by Gerhard Laus; Klaus Wurst

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: German
• Weight: 211 KB
• Volume: 91
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.200890085

✦ Synopsis

Abstract

The single‐crystal X‐ray data of akuammigine picrate hydrate (1⋅Picr⋅H~2~O) confirm the relative configuration of the indole alkaloid akuammigine (1) as epiallo (Fig. 1). With reference to the known (15__S__)‐configuration due to biosynthesis, the absolute configuration of the other stereogenic centers is thus given by (3__R__,19__S__,20__S__). Four crystallographically independent molecules are observed in the asymmetric unit (Fig. 2). Each of the alkaloid cations forms H‐bonds to a H~2~O and a picrate anion (Fig. 3). The H~2~O molecules are further associated by a H‐bond as indicated by the short O⋅⋅⋅O distance (Table 2). The conformation in the solid state of the picrate hydrate is now firmly established, and a cute H‐bonding motif is observed.