Configuration of the ring A methoxyl in delphinine and aconitine from the crystal structure of a synthetic intermediate, C22H30O5N.C2HO4

Abstract

The synthetic acid oxalate, CzzH30OsN.C2HO4, m.p. 189-192°C, crystallizes in the monoclinic space group C2/c, with eight molecules in a unit cell of dimensions a=23.972 (1), b= 10.346 (2), c= 18"656 (I) /~; fl=93.16 (2) °. The densities are: Dx= 1.373, Din: 1.372 g.cm -a. The structure was determined by the symbolic addition method from data collected at room temperature on a four-circle diffractometer using the 0-20 scan technique. It was refined by the block-diagonal least-squares method to R = 4.28 % for 3115 observed reflexions. Ring A occurs in the chair conformation, and the C(1)-methoxyl is in the equatorial position, cis to the nitrogen bridge. This finding makes it necessary to revise the configurations of the corresponding methoxyl groups in delphinine and aconitine. Pairs of cations are hydrogenbonded to pairs of oxalate anions, a centre of symmetry being located between each pair. Each cation is linked to two anions by one normal and two bifurcated hydrogen bonds.

Synthesis of Cardiopetaline via a Wagner–Meerwein Rearrangement without Preactivation of the Pivotal Hydroxy Group

“…Exploration of the toxic components of the plants has led to the discovery of a variety of diterpenoid alkaloids. Aconitine ( 1 , Figure ), the first such diterpenoid alkaloid isolated, is one of the most toxic plant poisons known to date and strongly activates voltage-dependent sodium ion channels . Lappaconitine ( 2 ), isolated from Aconitum sinomantanum , has been used as a class I antiarrhythmic drug that inhibits human heart sodium ion channels .…”

Crystal structure of dimethylammonium hydrogen oxalate hemi(oxalic acid)

“…The title salt constitutes a new example of dialkylammonium hydrogenoxalates and thus supplements the number of crystal structures resolved to date for this type of salt (Birnbaum, 1972;Thomas & Pramatus, 1975;Thomas, 1977;Gü ndisch et al, 2001;Warden et al, 2005). In addition, ISSN 2056-9890 and because of their capacity to easily develop hydrogenbonding networks, carboxylic acids and their derivatives are of great interest in the field of crystal engineering, leading to a large diversity of supramolecular topologies (Ivasenko & Perepichka, 2011).…”

Total Synthesis of (−)-Cardiopetaline

“…Norditerpenoid alkaloids, isolated predominantly from the genera Aconitum and Delphinium , are known for their extremely high bioactivities and have been harnessed as poisons or medicines. For example, aconitine (Figure , 1 ) is one of the most toxic plant poisons, as it strongly activates voltage-dependent sodium ion channels . The blockage of sodium ion channels enables lappaconitine ( 2 ) to be used as an antiarrhythmic drug .…”