Structure of spiradine A: X-ray analysis of spiradine A methiodide

Abstract

The crystal structure of the methiodide of the alkaloid Spiradine A was determined by three-dimensional X-ray crystallographic techniques. The crystals are orthorhombic, space group P2₁2₁2₁, with Z= 4 in a unit cell of dimensions, a= 14·04, b= 15·88, and c= 8·55 Å. The structure was determined from conventional Patterson and Fourier analyses and atomic parameters were refined by least-squares techniques to R 9·9% for 1752 independent reflexions. The absolute configuration was determined by the anomalous dispersion method.